Percentile Based Systems

Serious Paul · June 16, 2008, 01:08:29 PM

So I've never been a big fan of percentile based systems-although I admit much of my experience comes from Palladium, and not other systems. But at least one of my players is. So sell me a little on why you like Percentile Based systems, and which ones you like?

Have any of you retrofitted systems to use a setting that wasn't percentile based to be percentile based? How did it work?

flyingmice · June 16, 2008, 01:16:20 PM

Quote from: Serious PaulSo I've never been a big fan of percentile based systems-although I admit much of my experience comes from Palladium, and not other systems. But at least one of my players is. So sell me a little on why you like Percentile Based systems, and which ones you like?

Have any of you retrofitted systems to use a setting that wasn't percentile based to be percentile based? How did it work?

The strengths of percentile are its clarity and ease of understanding, simplicity, wide range of results, and ease of adaptation.

I changed Serenity on the fly to use my Cold Space ruleset. Nothing much was difficult except I had to add traits.

-clash

Caesar Slaad · June 16, 2008, 01:37:18 PM

I like percentile because 1) the probabilities are pretty implicit, and 2) you can do a lot with it. It's easy to tweak things around to get a result you are looking for.

That said, most published percentile based RPGs aren't real high on my list; Palladium is about the antithesis of it.

The one I do like is James Bond 007 because it uses percentile for resolution, but doesn't track skills and attributes in terms of percentiles, which is a convention I've never much cared for.

KrakaJak · June 17, 2008, 03:24:02 AM

Quote from: Serious Paul ;216415So I've never been a big fan of percentile based systems-although I admit much of my experience comes from Palladium, and not other systems. But at least one of my players is. So sell me a little on why you like Percentile Based systems, and which ones you like?

Have any of you retrofitted systems to use a setting that wasn't percentile based to be percentile based? How did it work?

In my opinion, the best percentile system is Unknown Armies.

You have 4 stats, and skills (but no skill lists, you just make skills up!). The thing i enjoy about it are the little dice-roll tricks. For Example: You make an attack roll, we'll say for karate 50%, You roll a 32. You damage equals 3+2, or 5. So you want to roll low AND high at the same time. The system is full of all kinds of clever little dice tricks like that.

Zachary The First · June 17, 2008, 07:59:54 AM

I tend to "think" in gaming terms in percentiles. I enjoy Rolemaster's open-ended presentation--roll high enough, and you keep on rollin'.

More to percentiles in general, I find it's a good baseline for folks to understand. ("+10% chance? OK!").

Nicephorus · June 17, 2008, 09:27:49 AM

My main experience is with Call of Cthulhu/BRP. As Slaad said, it's obvious what your chances are and it's easy to adjust things and know what will happen. I've had new players with CoC, handed them a character sheet, and told them "Wanna do something? Find the closest skill on your sheet and try to roll under it." and they jumped right in.

With some other dice systems, it's not so obvious how likely you are to succeed.

It's also gives you a flat curve with a fine level of granularity, which may or may not suit you.

Kyle Aaron · June 17, 2008, 12:32:58 PM

I think a percentile system has a few features, which you may find good or bad.

easy to understand what the numbers mean
easy to modify the numbers by a multiplier - "A hard task, half skill, easy task, double skill"
you can use one roll for several things:- eg for combat roll under skill to hit, reverse roll for hit location (roll 63 becomes location 36, etc), add the two numbers for damage; for non-combat roll under skill to succeed, the sum of the dice can be the time taken or quality of success, etc
if you want chance of critical success/failure to vary with skill level, just say something like, "if the tens and digits match, it's a critical."
improvement of skills through practice or xp can be hard to decide on a system for, things which give you +1% each time are really slow, more than that is too fast, and escalating costs (eg, "1xp for each of the first ten, 2xp for each of the second ten, and so on") can be confusing.
if you want the attributes and skills to relate to each-other, simply adding the two gives you numbers over 100% very quickly, so you need to have something like, "the base of every skill is 1/4 the governing attribute" or have a chart with attribute bonuses for skills, etc.
if you have a dis/advantage system, it'll probably have to be on a different scale to the attributes and skills; after all, what would "Enemy 23%" or "Lame 77%" or "Keen-Eyed 11%" mean?
on the same theme, what about hit points? It can be difficult to see how to simply relate loss of hit points to the attributes and skills, unless your attributes are your hit points.

kregmosier · June 17, 2008, 12:36:50 PM

BRP, no question.

As KrakaJack said, UA is very cool, but i like the setting more than the mechanics; the funky dice-tricks were just kinda off-putting to me, but everything else was sweet.

Pseudoephedrine · June 17, 2008, 12:40:45 PM

I'm a great fan of UA's system, and ran in an excellent conversion of Conan using it.

http://www.voidstate.com/rpg/Unknown_Ages.pdf

James McMurray · June 17, 2008, 12:45:11 PM

Quote from: Zachary The First ;216488I tend to "think" in gaming terms in percentiles. I enjoy Rolemaster's open-ended presentation--roll high enough, and you keep on rollin'.

More to percentiles in general, I find it's a good baseline for folks to understand. ("+10% chance? OK!").

This man has stolen my thoughts and presented them as his own.

gleichman · June 17, 2008, 07:02:52 PM

Easy to understand, it states the odds right on the dice as it were.

And I need to use them to get the game system balance I required in my fantasy.

J Arcane · June 17, 2008, 07:20:40 PM

Quote from: Zachary The First ;216488I tend to "think" in gaming terms in percentiles. I enjoy Rolemaster's open-ended presentation--roll high enough, and you keep on rollin'.

More to percentiles in general, I find it's a good baseline for folks to understand. ("+10% chance? OK!").

Almost every roll I make in most games I inevitably wind up calculating in my head as percentile odds anyway. Using actual percentages makes a for a pretty convenient shortcut.

Zachary The First · June 18, 2008, 07:34:54 AM

Quote from: J Arcane ;216900Almost every roll I make in most games I inevitably wind up calculating in my head as percentile odds anyway. Using actual percentages makes a for a pretty convenient shortcut.

I hear you.

Philotomy Jurament · June 25, 2008, 03:25:12 AM

Quote from: Zachary The First;217046I hear you.

Me too.

I like BRP. Lejendary Adventure is a pretty cool percentage-based system, too.

James J Skach · June 25, 2008, 09:00:00 AM

I played, recently, in a game of Roma Imperious with Hinterwelt (Bill) and we used the V2 of Iridium. It's more percentile based than the previous version (it has always been a mix).

I have to say, my first reaction was "so what do we use the d20 for again, then?" But after that 1 second, we all settled right in, and it worked nicely. He even does a thing to remove a roll by simply flipping the 10's and 1's to take the place of what would be the second roll...

Lot's of fun.