He rolled the percentile dice again. The numbers blazed up at him. Eighty One. High damage, even for an immortal.-Bimbos of the Death Sun The other side of the HP system is the damage system. Damage in most systems is an example of an effect system; it is usually the most involved effect system in an RPG because precision is required – the stakes are by default character life or death, leading to inclusion of detailed modifiers for things such as weapon modifiers (1), attacker Strength (2), and sometimes hit location (3). Damage usually includes a random variable (4) and may include a skill/to-hit bonus.(5). (1) Weapons: In HP-based systems weapons are often assigned different amounts of damage (exceptions including OD&D and Fighting Fantasy; potentially HERO which is more complex but where, IIRC, a weapon’s specifics can be designed by the player able to pony up enough points). Some systems give weapons multiple possible damage ranges e.g. Harnmaster separately defines Edge, Point and so on values for weapons (a detail most games are happy to ignore or abstract into the damage roll – like maybe a 1 on your longsword damage means you hilt-punched the orc in the snout); Palladium’s Ninjas & Superspies includes various unarmed damage ranges for one-finger-strike, punch, kick and so on, though fails to offer much incentive to use lower-rated attacks. All weapons being equal does give a player more freedom to customize to fit their concept, without ending up using something that’s sucky because the game designer failed to properly understand how a khopesh is meant to be used (the stupid shape is to go around an enemies shield, not so you can make free trip attacks; thanks, whoever wrote Sandstorm...), but this removes a layer of the crunchy/tactical elements of character design; it is generally better to design weapons to be equal rather than identical; a task often approached by adding different armour penetrations, special abilities, special drawbacks or attribute requirements to weapons, something designers manage with varying degrees of success. Of course, it can also be argued that some weapons (e.g. whips or lucerne hammers) should be uncommon choices because they aren't that good. (Some systems like 3E include special abilities like feats etc. that can power-up weaker options.
(2) Hit Location: some systems will modify damage for vital locations struck (e.g. head = double damage), while others assume this sort of thing to be part of the damage roll; for others damage points aren’t changed by location but the effects of X amount of damage might be different i.e. different limbs may be disabled, or a character may have less HPs in some areas (such as the head e.g. in Twilight 2000, Runequest).One example of what not to do with hit location would be the mind-boggling Swords’ Path: Glory (discussed here: http://www.therpgsite.com/showthread.php?t=21194 ); it uses hit location tables that cross-reference a rolled Impact and armour type to determine exact flesh depth penetrated and hence whether bones are broken, arteries slashed or so on. Unlike Rolemaster this was almost wholly a raw HP system – the hit location was randomly determined and final output of the table is simple a number of damage points and a shock roll % rather than a specific injury, making the outcome not much different to just rolling a damage die (compare the principle of Black Box design http://www.enworld.org/forum/general-rpg-discussion/226856-simulationists-black-boxes-d-d-4th-edition.html ). Also, SPG was meant to be plugged into a system where HPs inflated rapidly with level, despite its HPs being completely physical rather than representing “luck” or “rolling with blows” , and didn’t allow for any way to select hit locations or otherwise improve damage from character skills/higher attack rolls, making it in many respects then, less realistic than say Storyteller (?...though the idea of a layer of 'impact' calculation before damage calculation, something shared with HarnMaster, could have potential uses...?). Hitting a specific hit location may only be available as a result of a "called shot" in some games (2nd Ed. AD&D, Unisystem, Savage Worlds), or may be a result of a good hit roll (an idea that works better if attack rolls are DEX-modified, rather than STR-modified), or might be generated with a separate random roll (Runequest, Deadlands).
A "separate" roll can sometimes be generated as part of another roll i.e.
*Warhammer 1E/2E reverses the tens and ones places of the d100 to determine location. The future 40K games e.g. Deathwatch run into complications with autofire weapons such as bolters where a single hit roll can generate multiple hits (a success is one hit, +1 hit per 10% of attack margin, up to the full ROF); in this case the hit location roll is used for the first shot and a table lists where 2nd, 3rd, etc. shots land - following a sort of arc across the body e.g. Head is always Head/Body/Legs (or something like that).
As noted by Rob Muad'Dib later:
Top Secret/SI(Designed by Douglas Niles and published by TSR way back in 87, it used all kinds of cool/innovative bits in its design--ads/disads, stun/wound dmg marked as /X, luck points, etc) pulled two result from attacks for close combat/melee. You'd roll under your Attribute (plus small skill bonus), if you succeed, your damage was based on the tens die (a Price is right/blackjack mechanic) and the ones die determined hit location.
*One Roll Engine counts matches in a dice pool as successes for that number i.e. if you rolled 7,6,6,6,5,4,4,1 you got either three successes (damage) against location 6, or two successes (damage) against location 4. Potentially this method could be used with a damage roll in some games, if damage is generated additively from a set of dice, without having to use OREs core mechanic for all actions.
If randomly generated with a separate roll, hit location may be generated for just some results (e.g. hits that are criticals, or that do more than a certain amount of damage) or for all results. A rolled outcome might be modified in some circumstances e.g. it may be possible to 'block' a hit to the head in melee by taking a hit to the arm instead. HarnMaster arranges locations on a table lowest-to highest (with odds/evens determining left/right) so that a bonus or penalty can be added to the location roll for 'aiming high' or 'aiming low', without fully specifying where a blow is aimed.
Synnibarr has a rule where hit locations for shots are rolled but dealt to a % of hit points, which would work except that cybernetics add huge hit point bonuses to the general hit point pool (i.e. a character can be shot in the leg, and not disintegrate solely due to having an incredibly tough robotic arm).
How the hit location system works has a major effect on combat description by the GM/players. The GM is freer to improvise description without locations, whereas with more detailed rules the player might get to describe results more (based off the dice rolls/mechanics).
A couple of other determination methods use a silhoutte or body map: Aces & Eights' "Shot Clock" uses a d12 to generate scatter around a prechosen location (which is hit without scatter if the attack roll is sufficiently high), while Millennium's End uses an “overlay” (showing how much roll is made/missed by) over a “body map”.
Hit locations mostly provide a more realistic game, at a cost of more mucking around, but do tend to generate issues with certain damage types such as electrocution, shock, or poison – even falling – which are hard to allocate to single locations. Some systems may use different location tables for melee and ranged weapons.
I’ve occasionally thought that in cyberpunk type games where “organlegging” is popular, hit location tables might be useful for the GM to help determine what “treasure” is salvageable out of defeated opponents...(3) Strength modifier: the other common modifier applied to damage is for Strength; exceptions include 0D&D pre-Greyhawk, HarnMaster - with slight variation appearing in the most complex version, HarnMaster Gold, Rolemaster, and Legends of Anglerre; Amazing engine which claims Fitness adjusts it but doesn't say how much; 4th ed. D&D where various modifiers might apply; as well as the simpler Fighting Fantasy or Maelstrom which don't have an equivalent score. Tunnels and Trolls just gives more 'adds' for STR, so it improves to-hit and then indirectly damage based off difference between attacker and defender. Rolemaster adds Strength modifier to offensive bonus (to-hit chance) which indirectly ups damage and criticals (STR modifying result here is possibly weird as it gives specific, highly accurate and deadly strikes on high results). Shadowrun 1st Ed uses Str to modify target number of defender's soak roll. This tends to make Strength a fairly important statistic for damage in most games. Modifier is normally just an addition to damage, though Synnibarr gives characters a damage multiplier and Savage Worlds increases the step die rolled (the Strength die). A couple of games (Magic Quest, Legend Quest) have STR bonus based off # Str points above STR-minimum to use a weapon, instead of an absolute modifier (notably affecting dual weapon use since using two weapons has cumulative Str-required, so using them reduces Str damage bonus). D&D 3E applies 1.5x Str mod to two handed weapons and 0.5 for offhand weapons, so that TWF can't apply 2x Str mod easily; optional rules (Savage Species) extends the progression to x2, x2.5 etc. for monster weapons used three- or four-handed. (This sort of proportionality can be less messy with die pool/variable TN systems).
In a system, occasionally a weapon might get an extra bonus beyond the normal plus from Str, e.g. City of Terrors for T&T has an item, the 'war gauntlet' that 1/day power punches for 1d6 damage per Str point (whereas a normal fist is 1d and gets +1 'add' for each Str point above 12; the Gauntlet presumably gets that as an extra bonus as well).
GURPS calculates a character’s # d6s rolled for damage depending on Strength and whether the weapon is “Thrust” or “Swung”. The Forgotten Futures RPG was interesting in that Str only increased the probability of more damage rather than adding more damage automatically since it increased odds of a higher result (different damage descriptions are given for a 2d6 roll under ½ the Str (Body) value, a roll under full Str value, and rolling over).Systems may “mirror” the role of Con in determining hit points and role of Strength in determining damage; one might add and the other subtract damage equally (Warhammer). Or to try to build a system where a character can normally take 3 hits before dying, a character might add [1xStr mod] to damage and [3xCon mod] to HPs. Breaking this parallel leads to a noticeable balance issue in 3.x D&D, where a low Con cripples even a high level character (20th level = 20x Con modifier to HP). This sort of one-sidedness also occurs in “Aggravated Damage” (Storyteller), where the attacker still gets Str but the defender doesn’t get a soak roll using Stamina.Crossbows in D&D tend to be weaker than other weapons due to not adding Str modifier; later D&D versions added +Dex for parity, while Palladium (in their medieval weapons & castles book) gave crossbows a built-in equivalent STR. Another game where this really shows is Scion, where melee weapons can get Epic Strength bonuses (see
here).
See page 7 (post 69) for more on weapon Str minimums.
Large creatures don't always get enough raw bonus from Str to represent how nasty they are, so may get some sort of size bonus to damage (maybe equivalent to weapon type e.g. in 3E where size steps up damage dice). BRP e.g. Call of Cthulhu bases 'damage bonus' off a combined total of [STR attribute + SZ attribute] rather than STR alone.
*(4) the random variable; most systems use random roll of some kind for damage; exceptions include games where to-hit roll modifies damage instead e.g. Talislanta (see below), Dragon Warriors (damage set by weapon, no modifiers), and Tunnels and Trolls (damage = difference between attackers and defenders’ rolls; an odd system in that extra weapon damage dice also add to a character’s chance to hit). Rolemaster uses the attack roll on a table to determine hits of damage (no separate damage roll). High rolls generate criticals off a different table; the attack roll (modifier by attack and defense skills) determines what sort of critical is generated (A to E or so), with a new roll then being made on the critical table.
DC Heroes has attack success adding to damage, but also often generates a 'variable' nonrandomly, through attackers or defenders expending Hero Points to raise their effect or resistance values, or use of Hero Points to eliminate damage directly with 'Last Ditch Defense'. (cf. post on 'safety valves').
Games with fixed/fairly fixed damage ranges can have larger variables in cases where some of the normal damage modifiers/rules don't apply that well. Aberrant for instance has Teleport error (landing inside an object) deal 1d10 health levels of damage (rolled directly) when most rolls instead use a dice pool. A 3.x pit trap begins with a roll of d4 to see how many spikes the character lands on, then gives each spike an attack roll/damage roll as a dagger (which could perhaps mostly be abstracted to a single larger die if desired, although that would cause DR issues).
Highly polar rolls can work better for generating interesting results. For instance, a GM might use a damage roll for a missed attack to see how badly damaged a computer console is, which gives fairly fixed (uninteresting) results if the damage is also along a fairly narrow range.
*(5) the to-hit or skill bonus; Shadowrun 1E has fixed damage, modified by attack successes; in it weapons have varying "Staging" which is how many successes move a weapon up a damage code -light to medium, medium to serious, etc. Weapons with low Staging are more beneficial for highly skilled characters, however Staging is also the # of soak (Body) or Dodge successes by the defender that will drop the attack back a code so these weapons are less effective on high-Body targets, or high Quickness ones. A later edition of Talislanta has fixed damage by weapon, with 1/2 damage (partial success), x1 (normal) or x2 (critical). Storyteller (oWoD) adds successes to-hit to the damage dice pool. The to-hit add to damage can be thought of as one way to represent character skill. D&D doesn't add a bonus from the to-hit roll (except via criticals) but skills may apply a bonus to damage directly i.e. extra 'sneak attack' dice, BECMI weapon mastery, weapon specialization, or monk +1/2 level to damage in 1E.Note: post #28, above, has more about 'effect' in general- flow of data from margin of success to result and so on. Note that if a high dice roll increases damage, that can offset combat options or builds designed to roll lots of attacks at a penalty to 'critfish' for 20s or the like - a penalty to the main attack lowers damage, while an attack with a penalty deals less damage.
Damage-based rollsA very few systems have worked out how to take a damage value, and use that to determine a success chance/probability of related events. For example, in Marvel Super Heroes an energy blast doing 30 points of damage would be a Remarkable amount of damage, and that value could determine the likelihood of the blast setting a building on fire (i.e. using the Action table, 30 damage would give a normal success on a 36+ on d100..). Other systems have attempted to set damage-based DCs (consider 3E D&Ds “concentration checks” for spellcasters taking damage, Coup de Grace saving throws, or a high level rogues’ Defensive Roll ability) but this generally works poorly since damage is not scaled appropriately to give a d20-based DC. Essentially systems run from a Success Roll (die roll for success/failure)-àEffect; taking an Effect output and converting it back to a success chance is working backwards, and so is difficult. MSH works for it since attacks deal fixed damage; Mutants and Masterminds should allow damage-based checks as well, since its damage rolls are just DCs for checks. Savage Worlds almost but not quite manages it, since its damage roll is on a slightly different scale to other checks - the sum of 2 dice, instead of best of 2 dice (the original 1st printing SW had damage as simply a trait roll, and in some respects would function better for this than the modern system). A dice pool system could in theory handle a conversion back from Damage to Success roll, if the damage dice pool and normal task die pools had similar numbers of dice.Comparing say SW-1st printing and MSH, these work differently in that MSH has damage equal to 'attribute' (from which a check probability can be worked out), while in SW-1st printing damage is simply a check
itself - game mechanically there's no difference between rolling unarmed damage and making a Strength check to twist someone's head off. The SW system has most of the advantages of MSH i.e. capability to use damage as a DC for an opposed roll, but also allows damage randomization. Similar systems could (theoretically) work with damage that directly reduces attributes (like in T&T), whereas MSH's system isn't particularly compatible.
In a game like SW where damage is a 'check' there isn't much difference between a sword stroke and a save-or-die effect. In some ways its damage checks are better for that in that a SoD often doesn't consider all of the toughness bonuses a creature should have, such as size bonuses and the like.
One Roll Engine is perhaps scaled well to use damage as an opposed roll too (as damage simply equals to-hit successes, plus some weapon bonuses) though I don't know if any particular mechanics are built off this. Earthdawn is another system where damage is a normal task die roll (Strength + weapon specific modifier is used to work out the step die), though the final result is normally subtracted from hit points rather than being used for opposed rolls, normally; Air Blast uses damage vs. Strength for knockdown (in ED 2E), most other knockdowns etc. are complicated by considering Wound Threshold however.
Further thoughts on damage-based rollsActually, considering further there are probably 3 potential mechanisms providing usefully scaled damage amounts (from the damage roll of individual damaging attacks):
1) damage from one hit is on the same scale as attribute (fixed/proportional to attribute, say 3-18 if the system has stats that are rolled with 3d6), and can be assigned a check modifier accordingly, using the normal attribute bonus chart or attribute check rules. If not attribute, it could work if scaled as a skill check or other check.
2) damage is rolled as a check, identical to other checks (if it equals to-hit successes, or is a separate Strength check with limited weapon modifiers, as in original Savage Worlds, etc). The damage can be variable and is used as the target number for opposed rolls.
Or 3) damage is generated by a 'damage check' which is identical to other checks as above, but then a final amount is generated from this, not necessarily equal to check result e.g. actual quantities of damage can be assigned via a table. Make the damage check function consistently as an opposed value may limit some of the operations that would normally be possible with a table, like using an alternate table for smaller weapons; it also suggests that e.g. damage reduction/armour should apply to the check result rather than output damage number.
Setup 3) of course adds a table - and in the middle of combat - but generates fewer constraints to the designer with regard to how Hit Points must be scaled, and how the damage check must be scaled (the two things that have to dovetail with each other in the case of the other options).
A few systems use ad-hoc translations of damage to success chance, usually badly: the 2nd Ed. Complete Fighter lets the 'sap' manuever have a 5% chance of KO per point of damage (regardless of defender HP), while Superbabes has damage forcing the target to roll d% under its current HPs to not be knocked out. Modern Savage Worlds sometimes uses [roll penalty = number of wounds] e.g. cremefillian ingested poison in Low Life; maybe gearing down the damage too much?
(Hypothetically, you could imagine a system which has damage set up to work as a check value, and damage that isn't - call these fixed and unfixed damage maybe. In this case extra bonuses could give more damage, but at a cost of having the damage become 'unfixed' and no longer be useable for dealing stun, knockback etc. etc. That could be associated with e.g. weapons vs. spell damage.)
ElaborationsIf rolled separately, critical successes/failures on damage rolls could have other effects, like weapon breakage (e.g. a '1' for damage = a weapon breakage).
As an idea, a range of different special results could be generated for 'criticals' without a table, based on damage rolls, e.g. 'doubles' might 'roll up', each maximum die causes pushback and multiple maximum dice makes a target drop prone.
Legends of Anglerre (FATE) has a mechanism for damage where the overkill on creatures ("overflow") is directly applied to other creatures (if there's a stunt like Cleave) or converted into additional effects (movement, etc.). LoA is perhaps especially good at handling this since it lacks a second roll for damage or other damage modifiers i.e. for weapon type (explaining how using a greatsword increases movement would be difficult!); amount by which an attack roll succeeds becomes damage directly. In other games, T&T has no term for "overflow" but likewise lacks a separate damage roll and so readily e.g. lets damage be split between multiple targets.
Older systems in particularly may sometimes model blood loss as ongoing damage from injury, which accumulates until a wound is properly treated (e.g. LegendQuest). Because of extra book keeping this is rarely seen nowadays. In more recent games the Roma Imperious system had interesting blood loss rules, further complicated in its case by HP being divided up by hit location, meaning blood loss was also from particular locations, rather than being systemic. D&D 3E retains bleeding for dying characters only, who lose 1 HP per round until they stabilize, apart from a couple of specific weapons/monsters. A game may also abstract progressive weakening with occasional rolls to see if a character collapses, instead of continuing damage.
Other Effects of Damage In addition to HP damage, attacks might also cause 'knockdown' or 'knockback'. Systems here include DC Heroes, MSH (special colour result), High Colonies (based on damage before armour subtraction, if greater than Str - so lots of bullets can knock a character down), Runequest (I think replacing impales on special successes with some weapons?), and Rifts occasionally more or less by GM fiat (or whatever cases of GM fiat Kevin wrote down).
A damage 'threshold' can have other effects as well. D&D and some D20 variants have 'Death by massive damage' [for 50+ points, or a size-based amount] adding a save or die to large damage amounts. Some special attacks might also trigger based on N+ damage e.g. in Rifts the 'Xiticix killer' has a tentacle that enters and reams a target for extra damage if the original damage roll is 12+; in some games crits or Str bonuses etc. may modify this, or a 'base' amount only may be considered.
Critical hits - see page 14 (post #136) for more details on critical hit systems. Multiple dice for damage are reasonably common, which can scale up problematically at times. One comment in regard to scaling for systems e.g. 4E D&D
here There are people who think that if 1d8+4 is an appropriate amount of damage to take when you have 20 HP, then 10d8+40 is an appropriate amount of damage to take when you have 200 HP. In reality, the first has a huge random component (anything from 25% to 60% of your HP can be taken off in a blow), while the second is highly predictable (40% to 55% is the equivalent range) and takes 5+ times as long to evaluate. An example of this is the 4e damage per level charts, which presume "half dice, half fixed" has the same meaning at level 1 as at level 30, significantly making level 30 combat less exciting.
Some sample damage calculations, grouped into categories (
roughly parallelling the 'effect' categories in post #28 on pg 3):
Fixed damageFixed damage (per shot that hits) would potentially work well with a system where a roll determines how many attacks hit, which could then be applied as a multiplier. Fireborn is something like this (but is somewhat more complex and listed under 'dice pool systems' below)
Fighting Fantasy: 2 damage regardless of weapon. (Test for Luck for 4, or 1 if this fails). cf. Advanced Fighting Fantasy below (Table-based). In rare cases damage may be rolled - e.g. Space Assassin has blasters which do 1d6. Weapon type usually doesn't modify; an inferior weapon may penalize "Skill" (the rules in the books sometimes just treat losing a weapon as generic 'damage' to Skill, rather than an ongoing modifier; in which case picking up weird alien nunchucks/a sharp piece of fruit/a walrus as a weapon and then drinking a Potion of Skill to restore lost Skill, might be interpreted as meaning you are now proficient in weird alien nunchucks/fruit/a walrus).
Marvel Super Heroes: damage = STR or weapon material strength, whichever is lower, or power rating for powers. While damage is fixed, special success on the attack roll may add a Slam, Stun or Kill result. Being fixed, the damage has no problem with scaling up to cosmic level without choking on too many dice - a class 3000 energy blast just does 3000 damage, instead of having to roll 30d6 (or whatever).
Dragon Warriors: fixed base damage by weapon (1-6); Str also adds a bonus to damage.
BESM 3E : mostly fixed damage, although damage is doubled on a margin of 12+ and tripled for 18+. Characters add 'attack combat value' (to-hit bonus).
Varying Die Type [
i.e. an independently rolled die]
0D&D: 1d6 damage, regardless of weapon. The Greyhawk supplement adds alternate weapon damage and Strength modifiers/exceptional Strength for fighting men, as well as 'large-size' damage for weapons (e.g. a longsword is d8 vs. an orc or d12 vs. an ogre - maybe it does more damage cutting through more flesh, or this may be a game balance thing); 1st ed AD&D is basically the same as that. Swords & Wizardry White Box (a clone) has d6+1 for 2-handed except staves, d6-1 for small, with +1 damage on a critical.
(flat random damage IMHO is perhaps not optimal since its not much more effort or complexity to instead use a weapon die, or have a calculation off something instead of an arbitrary expression).
A few spells/effects use alternate systems e.g. fixed damage (a hellhound's breath doing damage equal to its HD in AD&D) or damage modified by AC [moving through the very pointy Plane of Minerals doing damage equal to d4+AC (not including Dex adjustments).
D&D 2E/3E: 1d4 to d12 +Strength modifier e.g. d8+Str mod for longsword. Potential critical for double damage on 19-20 (3E) or on 20 (2E). Strength modifiers start at 12+ in 3E and 16+ in 2E. Spells typically deal d6 to d8 per caster level. 50+ damage in one hit optionally forces a saving throw vs. death ('death by massive damage').
D&D 4E: variable # of weapon dice (by power) + key ability modifier + any additional special effects. Max damage on critical, +d6 per weapon plus. Some powers do damage on a 'miss' [=ability mod]; some feats likewise give that with weapons such as warhammer or scimitar, to balance their lower (+2, vs. normal +3) proficiency bonus.
Overall inflation in ability mods over D&D editions has tended to make the actual weapon die roll less and less meaningful (vs. 0D&D where a low roll might just scratch the orc, a high roll kill it); this changes the whole dynamic of combat from a series of life-or-death die rolls to a slow 'grinding' process (in part prompting need for more complex manuever systems to spice it up, although these are also good for involving player choice).
Black Streams: this is an interesting (free on drivethru) rules supplement for AD&D intended to let single PCs take on a dungeon solo. It takes the normal damage roll and vs. PCs steps it down [1= none, 2-5 = 1 damage, 6-9 =2, 10+=4]; PCs use the same table but deal damage in 'hit dice' e.g. a roll of '2' would deal 1 HD of damage and so kill a 1 HD orc. They also get a bonus class-based 'fray die' that works similarly.
Runequest/BRP: base by weapon e.g. d6 or d8 +damage bonus from [total STR+SZ] on table, with normal ratings giving +0 extra damage.
Savage Worlds: Explorer edition/Deluxe - Str dice + weapon damage dice (i.e. Str +d8 for sword). +d6 if hit roll succeeds by 4+; maximum rolls reroll and add. Shaken if roll exceeds toughness, +1 wound per 4 over. Str also heavily limits what weapons a character can wield, and so affects damage substantially (although a higher Str die can still roll a 1 - in unarmed combat particularly, Steve Erkel can 'roll up' and outdamage Arnie. Compare this to Forgotten Futures below, which has a slightly similar effect from a table).
SW 1st printing/2nd printing -Str trait roll (including wild die) + fixed weapon bonus. 1st printing gives +2 from per each 'raise' to hit (4 over Parry) (this was reduced in 2nd printing to encourage called shots). PCs had a big advantage on damage since they get both a wild die to it, and are more likely to get a 'raise' on the hit roll as well.
(see nDervish argues
here that damage scaling in SW tends to not work at higher levels due to the fixed 4/wound being a narrowing gap as number of dice increases).
SW damage does tend to generate occasional blowouts since there are several dice which can 'roll up' separately. A houserule might be to limit one die to rolling up; potentially you could even limit rolling up to the bonus die added from a 'raise', so that open-ended results become quite rare.
(
I also was recently working on a SW-derived system which was one-roll-only; in this a weapon did damage equal to either the Fighting die result (including rolling up as normal), or a separate damage die (usually larger, and including step increases for Str). 'Light' weapons dealt damage equal to the fighting-die only, with no extra damage roll; this has an effect of reduced 'critfishing' for TWF as this had two chances to roll up the Fighting die, off both attack rolls, but no damage die explosions.)
Ample Polyhedra: One friend's homebrew rpg "Ample Polyhedra" system, had a damage system reminiscent of Savage Worlds: characters had 1-4 'wounds' (1=Extra" to 4="PC") but instead of wound divisor being a set /4, each character had a 'toughness number' which was the divisor. A complication with that was that to keep criticals valid, critical dice were then also increased for high Toughness to cancel this out, making large creatures vulnerable to being stabbed in vital places e.g. Toughness 4 = +d8 damage on a critical (raise on attack roll), while Toughness 6 would give +d12 on a critical - even more damage so as to maintain a 50% chance of an additional 'wound'. A houserule proposed was to have normal damage wounds calculated using the Toughness as divisor, then add a separate critical roll not adjusted for Toughness i.e. d8 vs. TN 5 to get +1 wound added on to the final wound count.
The game treated armour as a toughness bonus, but this only helped against the first wound (a character with base Tf 6/+ armour 9 would take wounds on 15, 21, 27, etc.).
Cortex: damage = attack roll - difficulty, + probably a damage die (d0 unarmed). Strength modifies weapon damage only indirectly, by boosting the attack roll (for Str-based weapons). Str also does not limit what weapons a character can use.
Toon: almost all attacks do 1d6 damage, no Str [Muscle] modifier. The 'incredible strength' schtick, which has a fixed base instead of being Muscle-based, lets a character do +3 damage on a successful skill roll but gives combat penalties if the skill roll fails and opponent Fight roll succeeds. A few weapons do extra damage e.g. rayguns 2d6, bazooka d6+2.
Warhammer 2E: d10+Strength modifier +(fixed) weapon modifier, 10s explode (if a separate Weapon Skill roll is made, IIRC); subtract target Toughness.
Later SF Warhammer games this inflates with multiple damage dice sometimes e.g. base 2d10+5 for a bolter, with +1 dice & drop the lowest for its 'tearing' quality (greatly increasing chance of a 10 occurring and rolling up), increase # Wounds, and some creatures with Unnatural Strength or Toughness (e.g. Space Marines) double those modifiers.
Dungeon World: like 13th Age below, weapons deal a hit die based on character's class.
Talislanta: combines step-die with a basic table (d20+modifiers, 6-10 partial success, 11-19 normal, 20+ critical). In e.g. 3E most swords would do d10+STR score; with a 'partial success' damage is reduced by half and with a critical the damage is doubled. 4E just has fixed base damage, adjusted for the table in the same fashion. Spells deal around d4 per spell level (potentially outpacing HPs), again with a damage multiplier from the table.
Ork!-the RPG: this uses a d4 to d12 for stat rolls (skills checks roll a number of these dice equal to skill rating 1-5, and add them). Combat is a raw attribute roll ( i.e. one die) of attacker Str ('Meat') vs. defender Con ('Bones'), with armour/weapon each adding up to +5 bonus; this same modifier range is normal for opposed rolls, though the modifier is fairly harsh for stat rolls as these use only 1 die. Damage = one level per 3 points of difference, round up (characters have six wound levels, including the uninjured health level).
Amazing Engine: step die with a 'margin rating' (roll under this on ones dice of the attack d100 means "Body" damage rather than "Stamina"). e.g. knife d4/3 margin, club d6/2. Fitness (basically Strength) theoretically adjusts this, but how much is not listed! Margin rating can be adjusted by called shots or armour.
Maelstrom: varies by weapon e.g. staff d6, spear 2d6, sword from 2d6 to 5d6 by cost. There is no STR attribute.
Mercenaries get a special proportional damage bonus - d6 per 10 damage or fraction, counting rolls of 1-3 and ignoring 4-6 (a blackjack die pool!). This is then a two-step process where initial damage has to be rolled before the number of dice to roll is known (e.g. 10 damage would roll 1 bonus die, 11 damage = roll 2 bonus dice). Ignoring the effect of rounding up, this gives about a 10% average increase in damage (+1 per bonus die).
Metagene: uses a variable dice based on strength. What's interesting here is they slowed down the progression by going d4,d4+1,d6,d6+1,d8, d8+1,d10..etc..not necessarily a great choice, every 2nd increase has exactly the same average but different distribution (i.e. d8+1 and d10 are both 5.5).
Die Pool (additive)GURPS: variable number of D6s based on STR and whether weapon is swung or thrust.
The Fantasy Trip: variable number of D6s, by weapon; weapons useable are limited by character STR (roughly similar results to GURPS); only unarmed damage is adjusted by Str directly. Crits deal double or triple damage (4 or 3 on 3d6).
Cadillacs & Dinosaurs: firearms deal a number of d6s; monsters typically have a number of d6s (basically arbitrary; most are not rated with Strength). Melee/thrown weapons d6+Str score or half Str score.
13th Age: variable die type/additive. Damage is one die/level, with damage die based off class rather than weapon to allow free weapon selection, + [ability mod*tier]. Monsters deal a fixed amount of damage instead.
Star Wars D6: damage of multiple D6, for melee weapons this is a Strength check (+possible weapon bonus dice). Notable because this uses the same mechanic as normal task rolls. Targets roll Str to resist (+ armour?), with difference (on a table) determining if a character is stunned, wounded, incapacitated, mortally wounded or killed (3 wounds generate an incapacitated, incapacitated + a wound = mortally wounded).
Tunnels and Trolls:. available as free download on drivethru; extract of the core rules from the solo adventures here
http://www.freedungeons.com/rules/. Roll weapon dice (d6s) + combat adds (+1 per point above 12 in ST, DEX, or Luck) - [same total for opponent] = damage (before reducing for armour). Damage is finely defined by weapon 'adds' allowing for huge weapon lists (e.g dirk 2d+1, broadsword 3+4, scimitar 4d, warhammer 5d+1, greatsword 6d); where D&D has 'dagger: d4', T&T has a whole
table of dagger types ranging from 'Dirk: 2+1' to 'Scramasax: 2+5', and same for other types.
In 7E and later, 6s deal automatic 'spite' damage. [T&T combats can be very one-sided, so PC resource attrition through the adventure may occur mainly through 'spite' or through loss of spell points [ST/POW]).
Missiles do much more damage (opponent total isn't subtracted from combat total) but require a Dex roll to hit, and come with the problem defense that a miss means defense is 0 and melee damage against the archer becomes probably fatal (though in a group situation, this is mitigated by friends contributing to attack or taking a share of damage). A DEX roll can also be required to hit very agile opponents (Blood Bats in the 5E rulebook adventure) or dodge the attack of larger monsters - GM discretion- so that opponent roll again isn't subtracted. Monsters that don't fight normally and have to take the full attack of PCs are usually given a very high CON by fiat (e.g. the Con 90 giant mosquito in solo adventure Amulet of the Salkti).
Poison in T&T is very common and can multiply the final damage e.g. x2 curare, x4 dragon's venom. Early versions of T&T added the multiplier to initial die roll; I think later versions applied multiplier to final 'hits' instead, so that poison didn't increase chance of hitting, though this generates adjudication problems as characters would often be using two weapons - with only one actually poisoned - or adding their totals together in mass combat.
A couple of magic weapons -i.e. the Hero and Hopeless Swords, from the Naked Doom solo dungeon- generate a fixed attack each round, instead of rolling dice. This is also the case for one common attack spells (
Take That, You Fiend). TTYF deals [IQ attribute*spell level] damage, a horrendous amount; this is especially bad in 7E where a character's level itself is often [IQ/10], making a TTYF deal damage approximately equal to [IQ-squared/10]
As the 'attack roll' is made up of weapon damage dice, it limits a lot of possible manipulations of the dice pool - it doesn't make much sense to 'split' the pool or spend dice on combat moves since most fancy manuevers shouldn't be easier with a greatsword than a dagger, unlike if the pool represented fighting skill.
Superbabes: base damage d6 (punch) to 20d20 (clobbered with aircraft carrier) + Strength bonus measured in dice with an irregular progression (at higher levels, generally +d6 per 50 for a maximum of +22d6 at 1000 STR). The "Hit 'em Harder" power adds a further +d6 per level with a specific weapon (in example characters up to +6d6).
SenZar: weapon type generates a 'Damage Class' (base DC is set by weapon, can be modified by magic weapons), plus Str adds bonus dice; these are added together to get up to several D10s of damage. Some weapon enchantments can deal x2 or x3 damage; the system gives separate damage bonuses for a Natural 20 to hit (x2) and rolling 10 over the TN (maximized damage) - quite often both happen at once. 1st level characters are very squishy but gain HPs rapidly - a strange feature of the advancement being that while there's no balanced mathematical progression, characters dealing level-inappropriate piles of damage will level faster (by killing oversize threats) until they die or catch up in HPs. Spells instead deal fixed damage (= power points spent, max. cost capped by spell level), and monsters have what sort of dice they roll for damage fiat-assigned directly, rather than going via 'damage class'.
Infinite Power: damage is (like other rolls) a set of d8s added together, 8s add and roll over. A total over opponent 'damage limit' inflicts one 'hit' and 4 hits takes out a character. (This is based off the quick start rules but it seems there's no benefit to increasing damage beyond enough to hurt the target).
HERO: d6 Stun per point of damage class (e.g. per 5 STR). Body damage = 1 per die (except that 1s rolled on the stun dice are worth 0 damage, and 6s worth 2 damage). Typical combat is fairly nonlethal because chargen is complex, and due to genre conventions. Killing attacks do more Body but less Stun - in 6E, Body damage equals the full roll and multiply by d3 to determine Stun dealt.
Fuzion: multiple d6 additive. Dragonball Z for Fuzion apparently runs into hundreds of bonus dice, apparently with defensive dice subtracting (?) and average normally used unless a result is likely to be significant. # dice (or fractions like -1 per 10d) can be used directly in some calculations like penalty for combat manuevers or energy costs, rather than damage itself. The scaling issue shows the problem fitting DBZ to Fuzion rather than using a custom system (e.g. Marvel or DC Heroes for instance are better adapted to this sort of scaling problem, but their setup is intrinsic to their damage systems rather than something that can be just added on in a sourcebook.).
Other: Someone's DIY system on rpg.net
here has a table cross-referencing Str and weapon type, with the peculiarity that rounding off means optimal weapons shift around as Str goes up/down.
Die Pool (Count successes)(Dice pool games as above tend to have fixed wound tracks; partly 'soak' is easier with these, but also arbitrarily-large HP pools would require correspondingly large damage dice rolls - its more OK to go from roll d8 at 1st level to 4d8 at higher level, than to go from 5d10 to 20d10...)
Storyteller: [Str+weapon bonus] dice, counted at difficulty 6. Bonus damage dice from success on attack roll [Dex+Melee]; subtract target soak successes[Stamina].
Storyteller-descended Aberrant usually is similar (though soak reduces the damage pool without being rolled). IIRC one interesting case was that a teleport error would deal 1d10 damage (very unpredictable compared to the usual range).
One Roll Engine: damage = number of matches on attack roll (to location determined by the actual number) + weapon bonus damage.
Shadowrun 1E: damage set as Light (1), Moderate (3), Serious (6) or Deadly (all 10) damage levels, by weapon. Weapon skill roll extra successes equal to weapon 'staging' rating increase damage to the next step; weapons also define the target number to reduce damage for soaking with body dice ('power level'). Dodge dice are spent and add as bonus dice to the Soak roll (using the same target number!) but also cancel the attack completely if more successes are rolled than attack successes. Dodge dice have to be rolled separately (or colour-coded) due to their ability to cancel hits completely, so there isn't really any simplification from having dodge/soak be intertwined.
Surgery rules tie into the damage rules e.g. an organ transplant leaves a character with a Deadly wound. This works generally better than it would in a overly-variable-HP system, where X damage will kill some PCs and be a scratch to others, like high-level D&D fighters.
Blue Planet: a set three damage dice (d10s) are rolled against a TN of [base damage + Strength - target Toughness] giving a wound severity of 0 (glancing blow), 1 (minor), 2(serious), or 3 (critical). Each wound forces a stun roll (Will check) with a penalty equal to the severity; critical wounds also force a Fitness roll to avoid dying.
Arkham Horror is really a particularly complex boardgame, but system-wise is interesting since its virtually the 'count successes' version of Tunnels and Trolls. A character rolls their 'fight' score as a number of dice (5s or 6s are successes, with a blessing lowering TN to 4 or curse to TN 6. Weapons add bonus dice and the successes equal damage - if the monster isn't killed it deals damage. Therefore like T&T hit/damage is a single roll, though only one side rolls. Two weapons simply stacks the damage bonuses; one weapon (the axe) has a +3 bonus instead of +2 used two-handed. The 'marksman' skill lets a character reroll a fight roll once per game turn. Monsters can be 'physical immune' or 'magical immune' in which case a weapon of that kind adds no bonus, but the base Fight dice still always apply.
Fireborn: weapon base + an attack 'sequence' will include manuevers that add pluses to damage (e.g. Press +5), or that can instead give an extra attack. A peculiarity is that the detailed damage amount is then compared to a 'threshold' which will convert it back to a 'minor wound', or -1d penalty, -2d penalty, etc. The effect is that damage amounts are fine-grained and
look important (this weapon does 8, that does 9) but will frequently end up having no game effect (a kick for 4 or mace for 7 damage might both be a -1d wound for a Water 4 opponent). Or a -1 wound might become -2 instead because -1 wound level is already used up). An issue might be that attack 'sequence' might be metagamed to choose either multiple attacks or a 'press' depending on exact damage thresholds, if known?
Base + Margin of Success (or Table)Rolemaster: damage by attack roll on chart; possible critical rolls on high attack.
Army of Darkness (Unisystem variant): STR x weapon multiplier i.e. [Str+1] x3 for sword. Add attack success level (determined by table, generally +1 damage per 2-3 over minimum success value of 9+). Core unisystem uses varying dice types. The Buffy unisystem variant also notes that life point damage for shots/stabs is doubled vs. humans (after armour, though largely just extra addition in low-armour genres; halving armour vs. bludgeoning and revising damage calcs might've been better).
Unisystem tries to speed up combat by streamlining dice rolls, despite the hit roll adding to damage. NPCs or monsters use their average attack roll to work out the normal 'success level' of attacks and add that to the base damage, resulting in the same damage every time, while PCs refer to the table.
DC Heroes: fixed base found by comparing STR/target BODY on a table (0 if evenly matched, up to full attribute if resistance is zero), plus bonus damage from a high attack roll.
Over The Edge: attack roll (multiple d6) minus defense roll, difference is multiplied by a weapon damage factor (no Str score exists/ is factored in, unless its defined as an ad-hoc trait and used as the attack roll). Armour works as rolled absorption.
Fate Core: damage ('shifts' directly equals the difference between attacker Fight and defender Fight roll, or Provoke vs. Will for social combat. Weapon and strength provides no direct modifier - relevant Aspects are potentially createable but would typically affect damage via increasing attack roll rather than modifying damage directly. One example stunt, My Blade Strikes True, forces a target to take a consequence rather than simple stress, 1/combat.
Forgotten Futures: (
freerpg, link here) damage roll uses the normal resolution system (2d6 under stat). A roll is compared to Body (i.e. Str) or weapon "effect" for weapons such as guns, and each weapon has a table listing a result for if the roll is under 1/2 Body, under full Body, or over, with damage being one of four levels (Bruise, Flesh Wound, Injury, or Critical). For instance a rifle deals a Flesh Wound on a failed roll, an Injury on a success, with a critical of Critical/Kill (target rolls Body to avoid being killed). Armour modifies the "effect" number. Note that since the 2d6 roll is non-linear, the 'critical' result is less common, and that (as noted above) high 'STR' (Body in FF-speak) only increases likelihood of more damage, rather than giving a direct bonus.
Feng Shui (2E): Str+x by weapon or power base damage [usually +1 to +4], - opponent Toughness = wound points. Wound points may be used as a modifier e.g. 'Vengeance of the Tiger' lets character riposte after taking damage with plus to hit equal to wounds taken (probably unbalanced, but followed by a Con check with the same number as a penalty to avoid exhaustion).
HOL: . Weapons have a base Wounds, then weapon "Anguish Factor" (minus target Armour) is cross-referenced with a d6 'intensity' roll on a table to get a damage multiplier (which however only varies by x1 from the roll though e.g. a 4 adjusted anguish gives 1-2:x1,3-6:x2). A high attack roll adds +d6 to anguish factor. As noted above, characters all get 20 Health Levels.
Advanced Fighting Fantasy uses a simple 1d6 roll on a weapon-specific table e.g. a sword by roll in order is 2|3|3|3|3|4|5 (the last number, for 7+, is available only with special bonuses). This gives slight variation while keeping range of damage mostly compatible with original FF (where damage for a successful hit is always 2). See notes on "game hybridization/how to" - overcomplicated by back-compatibility with a very simple system. AFFs two editions handle 'Strength' differently; in 1E this gave +1 damage while in 2E it became a feat (equivalent) rather than a skill, and also IIRC just gives a +1 to the roll on the table i.e. much less of a bonus - the table downsizing the effect similarly to say Fantastic Futures' tables.
Chill: chill has named result levels like 'scratch' or 'critical', generated by attack result on a table, which fill up boxes on a health track that's generally similar to e.g. Fudge or Storyteller. Each result also generates an amount of 'stamina damage' which is set by the result level e.g. 2d10 or 4d10. System has some redundancies therefore, also, Str or weapon type don't modify damage.
Other Attack-Roll BasedUnknown Armies (d% roll-under), firearms do damage equal to the attack roll if you roll under your skill, up to a maximum for the specific gun. A roll of doubles (11, 44, etc.) gives automatic maximum damage).
(T&T above could potentially be grouped with this inasmuch as it too has wholly attack-roll-based damage, albeit that the attack roll is multiple dice additive).
The miniatures game 'Silent Death'
apparently uses a 3-die roll to hit (sometimes different dice types). Weapons are rated as 'low', 'medium' or 'high' damage, indicating which of the 3 attack dice is used as the damage roll also e.g. on a 3+4+5 attack that hit with a 'low' weapon, damage would be 3. Doubles indicated these added together, building in 'criticals'. (If you rolled 4,4,5, you could do more damage with the low weapon than the high one, 8 vs. 5.
General Note: Damage being a different subsystem to other mechanics can affect the value of stats modifying damage and/or hit points. Multiple damage sources can make e.g. Str bonus irrelevant, but more often a different subsystem scales up the importance of STR. In an extreme case, a Marvel Super Heroes character for instance uses attribute score for damage and table lookup to-hit, so a one-rank shift in Fighting stat might give +5% to hit (increasing damage per round by 10%), while the same increase to Strength might increase damage by 50%, 100% or more.
Thoughts in closing: many people consider it logical that the attack roll influences the damage - which can also in many games factor in character skill. Some core mechanics do not easily support this, and/or the additional calculations involved can be annoying or slow. Attack and damage being somewhat disconnected is sometimes desired e.g. Savage Worlds does this to encourage 'called shot' attacks. Its also argued that, for example, having damage only slightly influenced by margin of success makes random gunfire dangerous despite e.g. darkness or movement penalties, supporting an illusion of realism.
See also: damage for miscellaneous situations (falling, immersion, etc.) is dealt with in post #55.
Describing damage: most GMs are generally in favour of giving colourful descriptions of what damage looks like to players. Note that games with hit locations and etc like limit the GMs ability to extemporize here. Games where there are a lot of small damage quantities coming off an arbitrarily large HP pool are a dampener on description since it tends to be irrelevant and happen all the time; a player is more likely to notice/care if they have only a few 'large' hit points.