Hello folks,

I've posted here a couple of times about the fantasy RPG I'm developing with a few friends, and I've greatly appreciated the feedback and suggestions I've received thereupon. I'm currently knee-deep in developing the game's combat system; my goal is to create a system that is dynamic, reduces the divide between player choices and character choices, and make combat center around tactics rather than resource management. Towards these goals, I'm strongly drawn to the idea of simultaneous turns (inspired by this series of posts). Instead of each player/creature taking actions in turn, every character and creature would declare their intent simultaneously and then see how the chips fall (via opposed rolls and other mechanics). I've read over the Design Alternative Analysis Archive, and it seems like this is a relatively uncommon approach, so I wanted to see if you folks had any insight/suggestions to offer on the matter.

Short version of the core mechanic (for context): a success-counting dice pool system using three different sizes of dice: Standard (d6, output 0,0,1,1,2,2), Promoted (d8, output 0,0,1,1,2,2,3,3), and Demoted (d4, output 0,0,1,1). Checks are made by rolling (Attribute)+(Skill Ranks) Standard dice. Bonuses to your roll allow you to "promote" some number of dice up to d8s, increasing the number of successes you're likely to roll, and penalties "demote" dice to d4s, decreasing your odds. Demotions and promotions cancel each other out. Primary attributes are:

• Might (MGT) - Physical strength and brawn. Increases physical damage, damage resistance, and effectiveness of feats of strength.
• Finesse (FIN) - Accuracy and focus. Increases precision when attacking and makes critical hits more likely.
• Spirit (SPR) - Grit, fortitude, and force of will. Influences magical damage, magic resistance, and actions requiring mental fortitude.
• Agility (AGI) - Speed, grace, coordination, and reaction time.
• Perception (PER) - Insight and awareness of surroundings (social and worldly)
• Intelligence (INT) - Knowledge, wit, and, cunning.

Categories of Combat Actions. As it stands, I'm thinking of grouping combat actions into five general categories: Direct Offense, Indirect Offense, Defense, Movement, and Everything Else. There's a bit of a rock-paper-scissors relationship here (although it's not hard-coded, just a property of how the actions interact). If you choose an action other than Defense, any actions targeting you are rolled against a static target number equal to an attribute specified by the targeting action.

• Direct Offense actions attempt to directly injure or incapacitate the target. Generally effective unless target makes an active defense, because you're rolling Attribute+Skill vs. a static attribute.
  
• Indirect Offense actions seek to circumvent defenses and/or impair target's rolls, tilting the odds in your favor. Generally effective against Defending targets because active defenses only apply against Direct Offense, or because there's nothing to defend against (e.g., Assess/Focus).
  
• Defense actions (AKA active defenses) improve your defense and can allow you to turn the tables on your attacker (disarm, unbalance, counterattack, etc) if you beat their roll by a significant margin. If your roll is less than your static defense value, you ignore the roll and use the static value instead (so there's no risk of lowering your defense by making an active defense). Certain active defenses are more effective against certain forms of attack: Block is more effective vs. melee attacks, while Dodge is more effective vs. ranged attacks.
  
• Movement: move across the battlefield by making an Agility roll. If your opponent also chooses to maneuver, the Agility rolls are opposed (instead of being rolled vs. static). The winner gets control the distance, either closing to melee range, withdrawing, or maneuvering to a more advantageous position.
  
• Everything Else: sort of a catch-all, includes actions such as drawing/reloading weapons.
  

So that's the basic idea. Does this sounds workable? Does it sound fun? Any feedback will be greatly appreciated. I'll post my list of all combat actions shortly; if you'd like more detail on any aspect of the system, please just let me know.

Here's my preliminary list of the different types of action in each category. Note that a given action can be accomplished in multiple ways. For example, an Overpower attempt (to push your target around) could involve a physical shove, a shield bash, a flurry of attacks that force the target to yield ground, or a terrifying illusion that causes them to cower and retreat a step. A Block may be made with a weapon, shield, or a hastily conjured sheet of ice. Depending on the method, different attributes/skills than those listed may be used.

Direct Offense

• Strike (FIN+Weapon/Magic skill vs. AGI): attempt to directly injure your target
  
• Overpower (MGT+Brawl vs. MGT): forcibly move your target and/or knock them prone.
  
• Grapple (MGT+Brawl vs. MGT): once grappled, additional grapple attempts can be made to ruin target's day.
  

Indirect Offense

• Assess (INT+Insight/Knowledge): size up your target, looking for exploitable weaknesses. Successes can provide a variety of useful effects from general information (e.g., "target favors Dodge and indirect offense") to offensive/defensive bonuses. Most importantly, benefits from Assessment can be easily shared with allies (talking is a free action, after all).
  
• Focus (PER+Awareness): attune yourself to your target's movements, at the cost of penalizing offense/defense vs. other targets. Gains give a bonus to offense/defense rolls against the target, and in some case cases might grant some predictive ability (allows you to pick two actions per round, deciding which one to use after the target has declare its action).
  
• Aim: gain a bonus to your next Strike against the target equal to your PER.
  
• Feint (INT+Deception vs. INT): not sure what this should do, actually...
  
• Target Weapon (FIN+Weapon skill vs. FIN): gains knock the weapon out of the way, penalizing the target's next attack/block/parry with that weapon. A significant success allows you to disarm your target.
  
• Unbalance (AGI/MGT+Brawl vs. AGI): gains penalize target's AGI and FIN. A significant success allows you to knock them prone.
  
• Taunt (INT+Deception vs. INT): if successful, opponent must directly attack you next turn.
  
• Intimidate (SPR/MGT+Intimidate vs. SPR): if successful, opponent must Defend next turn.
  
• Reposition (AGI vs. AGI): attempt to flank/outmaneuver target while staying in melee range.
  

Defense

• Block (MGT+Block): bonus v. melee, penalty v. ranged
  
• Counterspell (SPR+Magic)
  
• Dodge (AGI+Dodge): bonus v. ranged, penalty v. melee
  
• Parry (FIN+Block): bonus v. melee, penalty v. ranged
  

Maneuver

• Engage: attempt close the distance between you and your opponent. If you fail to beat your opponent's AGI, they may withdraw in order to maintain distance. If your opponent is wielding a Reach weapon, you must beat their AGI or they get a free attack.
  
• Disengage: withdraw from melee combat. If you fail to beat your opponent's AGI, you must either stay put or suffer a free attack from your opponent. If both combatants choose to Disengage, no roll is made; both automatically succeed ("Screw this, I'm outta here!")
  
• Intercept: If your movement conflicts with an opponent's move, you both make opposed AGI rolls to determine the outcome. Winner gets his/her way.
  

Other

• Prepare Item: draw/reload a weapon, prepare an explosive, &c.
  
• Assist Ally
  
• Reconnoiter: make a PER+Awareness check to spot things you may have missed before.
  
• Sustain: continue a spell's effects
  
• Empower Magic: power up to unleash formidable magic. AoE vectors would probs require at least one Empower Magic action.
  
• Recover: end an ongoing status effect. Some effects require a roll (confusion, sleep) while others do not (unbalanced, prone).
  

Assorted Modifiers

• Some actions leave you Defenseless; you can't attempt an active defense, and your static defense is reduced to 1.
• Heavy melee weapons give bonuses to Overpower and Block
• Light melee weapons get bonus to Feint and Parry, penalty to Overpower and Block
• Crossbows and firearms must be reloaded after firing; crossbows take one Prepare Item action to reload, while firearms take two.
• Some hugely powerful magic might require multiple Empower Magic actions to power up. This creates (IMHO) a nice equivalency between martial and magic classes; both have their standard attacks, as well as bigger limit-break attacks that can only be used effectively if they have the opportunity to power up.

I'm still brainstorming actions to add to this list; if there are any cool actions or combinations you think I should include, please let me know!

It sounds interesting but I'm missing a few links in the chain from a quick read - how do multiple action costs interact with the simultaneous turn system? Normally "time taken" systems are based on tick or action point economy games, how does imposing a time cost function with simultaneity? Are you translating them directly to penalties?

Also have you actually played this through, my own experience with simultaneous systems is that you need a secondary temporary record so that death spirals and so on don't interfere with primary actions despite the player acting effectively after the monster.

Quote from: Synchronicity;704779I'm strongly drawn to the idea of simultaneous turns (inspired by this series of posts). Instead of each player/creature taking actions in turn, every character and creature would declare their intent simultaneously and then see how the chips fall (via opposed rolls and other mechanics). I've read over the Design Alternative Analysis Archive, and it seems like this is a relatively uncommon approach, so I wanted to see if you folks had any insight/suggestions to offer on the matter.

I've been treating combat as simultaneous since AD&D.  There is actually a little combat narration in the 1st DMG that hints at how to GM it.  I've been doing it for >30 years now.  It is of course, easier with smaller groups.

I know it`s not fantasy, but Traveller 5 combat is treats everything in a similar way (or it seems to me). Have a look at how Marc Miller has engaged with abstract combat in T5.

Did a quick scan through the linked post series.
Simultaneous turns for declaration of intention don't necessarily mean simultaneous action resolution; you can have intention declaration before initiative, for example, as in 2nd Ed. D&D or oWoD Vampire. I'm gathering you mean simultaneous for both, though.
I don't see why it wouldn't be workable... In the case of PvP combat you might need to write down actions or the like, but generally I guess you could trust the GM to declare action after the players. Assess seems to touch on the idea of perhaps predicting the opponent's move?

The actual action list seems OK, though its always hard to assess any given rule when its just listed as a component, out-of-context with the entireity of the system. I think it may be tricky to balance 'defend' type actions as a viable combat action vs. attack, though.

IMHO (I don't have any actual expertise in beating people up though the purpose of a Feint is normally to land an attack when you otherwise couldn't by basically distracting an opponent with a fake attack. Its one of those combat actions which you could leave out if you wanted by assuming that a PC with a high combat skill is occasionally feinting or whatnot as appropriate, without it being declared. ('Engage is another action that I suppose often falls under the zone of abstraction in many systems').

The only system I know that does simultaneous turns is Burning Wheel and its siblings (Mouseguard, Torchbearer, Burning Empires).

Luke Crane's not a popular person here (to say the least!) but the combat mechanics in his games (and BW gives you three similar ones) are at least worth looking at as an example of simultaneous turn systems.

A system with simultaneous declaration and resolution can be helped with a heaping helping of basic game theory (as in, the mathematical kind), as game theory provides pretty useful tools in terms of decision matrices and evaluating the choices that players have available to them in games, as well as things to avoid (you probably want to avoid any pure strategy equilibriums, for instance).

Quote from: robiswrong;706070A system with simultaneous declaration and resolution can be helped with a heaping helping of basic game theory (as in, the mathematical kind), as game theory provides pretty useful tools in terms of decision matrices and evaluating the choices that players have available to them in games,

No need for all that if you have an experienced GM.

BSJ got it in one. Sim. decl. has already been done; sim. rez. shows up in a few games. Adding sim. rez. to games with sim. decl. (which is just a format of receiving table comm.) basically just throws away init. rules, assumes a larger round time frame, and there you go.

One of the fastest ways to implement this is paper & pencil (or personal dry erase boards), and an egg timer. Have everyone write what they do beforehand in secret, no collusion allowed, run an egg timer, and then everyone reveal all at once and resolve. Limiting allowable in-battle chatter with the egg timer is very useful and speeds up the game tremendously. It does create significantly more chaos until people adjust, but it does reward proper discussion of tactics beforehand.

Thanks for the feedback folks! Gonna try to respond to y'all in turn...

Quote from: The Traveller;704800It sounds interesting but I'm missing a few links in the chain from a quick read - how do multiple action costs interact with the simultaneous turn system? ... Also have you actually played this through?

Truth be told, I'm stilling trying to figure out how to handle multiple actions by one character (i.e., a PC attempting to Prepare Item AND Strike in the same round). I'm leaning towards the Savage Worlds model, where multitasking imposes a (fairly steep) penalty to both actions; any suggestions on this front would be greatly appreciated. Alas, I haven't had the opportunity to playtest this yet, but it will probably need some way of keeping track of impending penalties (I say impending because any penalties inflicted in a given round do not actually go into effect until the next round, to avoid the death spiral effect you described).

Quote from: Arduin;704803I've been treating combat as simultaneous since AD&D.  There is actually a little combat narration in the 1st DMG that hints at how to GM it.  I've been doing it for >30 years now.  It is of course, easier with smaller groups.

Oh snap, I'll look that up. I always assumed it worked the same as in 3.5 and 4e, but we all know what happens when one assumes...

Quote from: BarefootGaijin;704814...Traveller 5 combat is treats everything in a similar way (or it seems to me).

Thanks, I'll take a look!

Quote from: Bloody Stupid Johnson;704839Simultaneous turns for declaration of intention don't necessarily mean simultaneous action resolution; you can have intention declaration before initiative, for example, as in 2nd Ed. D&D or oWoD Vampire. I'm gathering you mean simultaneous for both, though.
I don't see why it wouldn't be workable... In the case of PvP combat you might need to write down actions or the like, but generally I guess you could trust the GM to declare action after the players.

Yeah, my plan is to have simultaneous declaration as well simultaneous resolution. Because PvP isn't a huge part of the system, PC actions would probably just be announced around the table, although there's always the option of writing intentions down if the in-game situation calls for it.
 

Quote from: Bloody Stupid Johnson;704839Assess seems to touch on the idea of perhaps predicting the opponent's move?

I actually was thinking of putting that under Focus. Still not exactly sure of the implementation, but would probably involve being able to pick from two possible intentions after the target declares its intention.

Quote from: Bloody Stupid Johnson;704839I think it may be tricky to balance 'defend' type actions as a viable combat action vs. attack, though.

In my mind, Defense is a viable option for two main reasons: first, combat is fairly lethal, so avoiding injury is a worthy goal in itself. Second, beating your attacker's roll with an active defense can allow you to take action against them (e.g., trip, shield bash, disarm, counter-attack), so choosing to go on the defensive doesn't mean forgoing an opportunity to disadvantage/hurt your opponent. I agree that balancing will be tricky, however.

Quote from: Bloody Stupid Johnson;704839The purpose of a Feint is normally to land an attack when you otherwise couldn't by basically distracting an opponent with a fake attack. Its one of those combat actions which you could leave out if you wanted by assuming that a PC with a high combat skill is occasionally feinting or whatnot as appropriate, without it being declared.

This would be a completely logical way of handling it, but I do like the idea of Feinting as a discrete tactical choice . Hmmm, will need to meditate on this...

Quote from: robiswrong;706070The only system I know that does simultaneous turns is Burning Wheel and its siblings (Mouseguard, Torchbearer, Burning Empires).

Awesome! I'll read up.

Quote from: robiswrong;706070A system with simultaneous declaration and resolution can be helped with a heaping helping of basic game theory (as in, the mathematical kind), as game theory provides pretty useful tools in terms of decision matrices and evaluating the choices that players have available to them in games, as well as things to avoid (you probably want to avoid any pure strategy equilibriums, for instance).

Thanks for the tip! I'll admit I'm not terribly well versed in game theory (beyond Prisoner's Dilemma-type stuff); any particular aspects you think would be especially important? Also, would would a pure strategy equilibrium look like in this system?

Quote from: Opaopajr;706184One of the fastest ways to implement this is paper & pencil (or personal dry erase boards), and an egg timer. Have everyone write what they do beforehand in secret, no collusion allowed, run an egg timer, and then everyone reveal all at once and resolve. Limiting allowable in-battle chatter with the egg timer is very useful and speeds up the game tremendously. It does create significantly more chaos until people adjust, but it does reward proper discussion of tactics beforehand.

I am totally adding the egg timer thing as an advanced rule; that sounds like a blast! However, I think I might allow collusion in most cases, except when the in-game situation precludes it (PCs are sneakily setting up and ambush, or are otherwise unable to communicate with each other). One of the main things that attracted me to a simultaneous-turns system was its potential for teamwork: rather than the spotlight moving around the table, everyone gets to put their heads together and try to throw together a plan of action. It'll be tricky to avoid analysis paralysis, but hey, that's where the egg timer comes in...

Quote from: Synchronicity;706244Thanks for the tip! I'll admit I'm not terribly well versed in game theory (beyond Prisoner's Dilemma-type stuff); any particular aspects you think would be especially important? Also, would would a pure strategy equilibrium look like in this system?

Basic understanding of decision matrices is useful, and basic concepts like dominated strategies.

A pure strategy equilibrium occurs when both parties in a game are in a position that they can't improve their outcome by changing their strategy unless the opponent *also* changes their strategy.  Not sure if you've got any of those without working through your examples...

An example of a pure strategy equilibrium might be a standoff - both parties are behind cover.  If both parties run, they get away (which is better than being stuck).  But if only one party runs, the other will shoot them.

The 'pure' refers to the fact that the strategy is to do the same action each time.  A 'mixed' strategy involves randomly picking different options - for example, in RPS picking 1/3 Rock, 1/3 Paper, 1/3 Scissors is a mixed strategy equilibrium.  Mixed strategy equilibriums aren't really a problem, since few people are really random enough to not be exploitable.

As far as multiple actions go - what's the reasoning behind wanting them?  It seems that just keeping to a single action is probably sufficient, as multiple actions will likely either always be a good idea, or never be a good idea (except for extreme edge cases).

Quote from: Synchronicity;706244Alas, I haven't had the opportunity to playtest this yet

Playing it through is like turning on an engine, you'll find out pretty quickly what works and what doesn't. Even setting up two to five characters by yourself and having them fight it out can be illuminating. This is also handy for revealing issues like clunky awkward time consuming rules that wouldn't be immediately obvious otherwise.

Quote from: The Traveller;706254Playing it through is like turning on an engine, you'll find out pretty quickly what works and what doesn't. Even setting up two to five characters by yourself and having them fight it out can be illuminating. This is also handy for revealing issues like clunky awkward time consuming rules that wouldn't be immediately obvious otherwise.

+1 to this.

I'd also go into it with an idea of the *types* of play/decisions/outcomes you want from the system.  Design is often best if approached in an iterative fashion - try something, see what it does, improve it, ad nauseum.

But to do that effectively you need something to measure the current status against.

One thing to note in playtesting is that 'full defense' is much more of a good option in a several-PCs-vs.-one-guy scenario.

Quote from: robiswrong;706252As far as multiple actions go - what's the reasoning behind wanting them?  It seems that just keeping to a single action is probably sufficient, as multiple actions will likely either always be a good idea, or never be a good idea (except for extreme edge cases).

I would comment that multiple actions rules are a fairly neat baseline mechanic for handling modifiers for a variety of tasks, if they're done well. Firing while running? Multitasking penalty for movement and shooting. Two weapons? Multitasking penalty. Lifting a weapon that's too heavy? Roll to push your Strength + a penalty. Dying? Roll to stay conscious as your first action and then a penalty to whatever else you're doing. Setting the penalty can be a delicate affair, though; it can be one of those things where its very difficult for a PC to tell when is a good time.

PS Tunnels and Trolls and (from hearsay) Torchbearer both use simultaneous resolution.

I wrote a card/board game that used cards to resolve combat.

Each character  had a prowess score that determined what cards you had access to. Some character had special combat cards due to training equipment or whatnot and some skills/magic gave you advantages like play two cards and take best result.

In combat both players selected a card at random from their opponent's pool of cards (this was to prevent marking)
You compare cards and the defender takes the difference in damage and any special effects are applied.

simple fast and entirely customisable.