What are some rules/mechanics you've picked up from one game to use in another?

I'll start with a few examples:

Rolemaster's Crit Charts:  I use 'em for Palladium Fantasy, I was considering coverting them for Epic (link for those unfamiliar), and I'll use 'em every chance I get, even if usually only for "crits" in whatever system I'm using.  They're usually easy to convert, my players love 'em, and they bring a lethality and unpredictability to games I like.

Burning Wheel:  "Let It Ride".  I know this isn't unique to Burning Wheel, but it did a really good job of framing some good GM advice as far limiting player dice roles in scenes.  

FtA!:  Haven't done it yet, but am considering how "stunting" would work in a few other systems of choice.

I also use "Mulligan Stones" and sometimes some an added Talent/Bonus/Quirk/Flaw system, but that sort of thing can be found in several different games, and depends on what I'm running.

In a current Shadowrun play-by-forum with randomized background (including race choice), I added the lifepath from CP2020. It really enhances the randomness of the game prep and moved me yet again to a character concept I would never have thought of before.

Otherwise, I steal ideas too often to even _remember_ an exhaustive list, let alone write one down.
Just to name a few influences in my current homebrew, not necessarily in order of importantness: Shadowrun (basic premise and adventure structure), CP2020 (smaller stuff like acid usage to damage armor), TRoS (tactical pool usage for everything interesting), Rich Burlews D&D house-rule for Diplomacy (influenced heavily social interaction rules), The Shadow of Yesterday (Keys, although strongly twisted and watered down to enhance instead of hinder an adventure game), the German RPG Midgard (artifact creation as a major way to use magic), the rogue-like Decker (difficulty and payment progression)... I'm sure I forgot some.

I'm not familiar with Rich Burlew's Diplomacy rules.  Is it in a book, or would you happen to have a link?

Quote from: Zachary The FirstI'm not familiar with Rich Burlew's Diplomacy rules.  Is it in a book, or would you happen to have a link?

It's on his homepage: http://www.giantitp.com/articles/jFppYwv7OUkegKhONNF.html

D6, in its current incarnation, simulates quick-draw contests by letting you take dice off your attack skill and put them on your Initiative roll; I'd use a mutation of that elsewhere, I would.

The 1PG system has a vehicle combat option where two combatants make opposed rolls to jockey for position, etc.; a certain margin of success translates into a certain bonus on a roll down the road, in the same combat.  I would use that for swordfights and stuff in other games: Maybe you just spent three rounds rolling higher on your Fencing skill than Monsieur Armand LePetomaine did, but you haven't actually hit him yet. THIS round, though, you'll be adding that +5 you've been building up...

Quote from: Dr Rotwang!D6, in its current incarnation, simulates quick-draw contests by letting you take dice off your attack skill and put them on your Initiative roll; I'd use a mutation of that elsewhere, I would.

I wonder if they picked that up from the StarCluster System, or came up with it independently. In SC you can also do the reverse - putting points/dice into your chance roll from your initiative, and you can put points/dice from either into damage/quality and the reverse. SC 2 came out before the current d6, though long after the original.

-clash

Quote from: Dr Rotwang!The 1PG system has a vehicle combat option where two combatants make opposed rolls to jockey for position, etc.; a certain margin of success translates into a certain bonus on a roll down the road, in the same combat.  I would use that for swordfights and stuff in other games: Maybe you just spent three rounds rolling higher on your Fencing skill than Monsieur Armand LePetomaine did, but you haven't actually hit him yet. THIS round, though, you'll be adding that +5 you've been building up...

That is a seriously cool idea.

I guess the origin of the initiative/action trade-off is CP2020 with its Haste Rule - you can gain +3 on your initiative roll, but suffer -3 on every action in that combat round.
Have to check if it originally even was one of the many tweaks to Interlock in Walter Jon Williams' Hardwired from '89...

Quote from: SkyrockI guess the origin of the initiative/action trade-off is CP2020 with its Haste Rule - you can gain +3 on your initiative roll, but suffer -3 on every action in that combat round.
Have to check if it originally even was one of the many tweaks to Interlock in Walter Jon Williams' Hardwired from '89...

Cool! I wasn't claiming to have inventied it myself, btw. From the credits pages of any of my games: "Special Thanks also to David Johansen for the concept of trading chance of success for quality of success. From his excellent RPG "Galactic Adventures." Used here with his permission."

David may have independently hit on it, but I didn't. Since I've never read or played CP, d6, or Hardwired, I never came across it before David's GA.

-clash

Quote from: flyingmiceCool! I wasn't claiming to have inventied it myself, btw. From the credits pages of any of my games: "Special Thanks also to David Johansen for the concept of trading chance of success for quality of success. From his excellent RPG "Galactic Adventures." Used here with his permission."

David may have independently hit on it, but I didn't. Since I've never read or played CP, d6, or Hardwired, I never came across it before David's GA.

I wasn't accusing you of theft - such stuff happens to myself all of the time when I write games, especially with such minor ideas. (For instance, I once had the idea to make range modifiers for ranged combat easier - take just a plain number x, and for every x metres distance you suffer -2 on your roll.
And then I grabbed Cthulhu for the first time, and I saw that someone else had exactly the same idea 20 years before me.)

I've just checked Hardwired - it isn't there, and I don't have the first edition of CP to check if it was already around back then. The 2020 edition offered this option however definitively.

I pretty much use Exalted style stuntung in everygame I use.

Either as a bonus to dicepool in dicepool based games, with a 2 die stunt also providing an expendable resource and a 3 die stunt also providing experience point(s).

In D20 I convert it to +1 +3 and +5 stunts. Just use the stunt as a circumstance bonus. +3 gets a expendable resource (like a hero point or whatever) a +5 nets the player Level x 50 XP.

For those of you that don't know how Exalted stunts work, they're all about describing your players actions in cool ways. A basic description "I pull out my sword and hit them in the head with it, HARD!" gets them 1 bonus die to their dicepool on their roll and if they succeed an extra essence point. More elaborate descriptions get 2 dice, "I draw my sword quickly as to have sparks shoot from it's sheath, mouthing a prayer I bring the tip of my blade through his forehead", succeeding returns 2 essence to your coffers and a willpower. A 3 die stunt is a game stopper, a description so awesome...everyone playing just stops and goes "whoa"; A three die stunt nets you 4 essence, a willpower point, and an experience point.

Well, I steal ideas all the time. I stole the concept of the "seesaw trait" - where the sum of two opposed traits is static but the traits themselves aren't - from Pendragon for "Honor/Practicality" in IHW. Love it! Works a treat!

Lots more stolen ideas than that!

-clash

i added the hit locations etc. from mechwarrior 1st ed. to my traveller game.  the players liked the additional level of carnage.  i would also occasionally rule that location crits (doubles) would just off mooks, rather than worrying about a punctured lung for guard #4 or whatever.

I'd use Spycraft dramatic conflicts (especially chases) with any D20 game. Basically, sorts the conflict into conflict rounds. Each round, each player selects a strategy with different potential results, but most are aimed at shifting the "lead" in your favor. The lead starts around 5; at 0, the predator wins (disables prey vehicle, catches them, etc.). At 10, the prey escapes.

I'd use Traveller D20 starship combat in any D20 SF game. It creates roles for the whole crew during combat, so you just don't sit by while the pilot and gunners have the fun.

I used Burning Empire Instincts in a Spycraft PBP. Not quite the intention, but it let me post (appropriate) actions for PCs when they players aren't online and I want to keep things moving.

I'm really considering working the Spirit of the Century "Novel" character generation sequence into other games, to establish connections from the beginning.

Quote from: Caesar SlaadI'd use Spycraft dramatic conflicts (especially chases) with any D20 game.

Seconded. I used them so far in SWSE, but will do it in D&D and Modern as well.