What are some good systems to plunder for game design ideas?

[Greywander]

I've long wanted to design an original system, but it's a tough thing to do when you're not familiar with a broad set of systems.

Recently, my sister offered to DM a game of 7th Sea, a game she kickstarted but hasn't had a chance to play yet. (We haven't started yet, so I might be misunderstanding some of the rules here.) I was reading over the rules and I can tell this game isn't for me. It's highly narrative focused, and to call it "rules-lite" would be an understatement. You'd think ship customization would get a dedicated subsystem as complex as D&D's magic system, but nope, all ships are identical; doesn't matter if you have a sloop or a man'o'war (you can get upgrades for your ship, but the type of ship is entirely cosmetic). Firearms have special rules in that they do extra damage, but there's no equipment section so I'm not sure how one is meant to procur them. Can I... can I just start with a dozen pistols?

Anyway, despite my misgivings, there's one aspect of the rules that intrigues me: the core resolution mechanic. When you attempt an action, you make a roll to generate a number of successes (called "raises"). To complete the action you are attempting, you'll need to spend a certain number of successes, but that's not all you can spend them on. Each action also comes with potential Consequences, negative effects that you can nullify by spending a success on them. An action can also open up Opportunities, some kind of extra bonus that likewise requires spending a success to take advantage of. The example used in the book was running out of a room that was on fire. Attempting to flee the room costs one success to carry out the action, comes with the consequences of receiving two wounds due to being burned (each of which can be negated by spending a success), and you also spot an important looking document about to be consumed by fire that you can grab on your way out.

What intrigues me about this mechanic is that it's not a strict pass/fail resolution. More or less, you get degrees of success, and then spend those like a currency to improve the situation. If you have four successes, then you can carry out the action "perfectly", i.e. you flee the room without getting burned and grabbing the document. (I believe you can also spend successes on additional actions, e.g. if you were being chased, you could topple a bookcase to block the door before you flee. So if you had more than four successes, you could find things to spend them on.) If you only have three successes, you can still "pass" the check, fleeing the room without taking damage, but you wouldn't grab the document. Or you could decide that grabbing the letter is worth more to you than preventing a single wound of damage. What's interesting is that this power is given to the player to make that choice. With only two successes, you can eat the two wounds and still flee with the letter, or give up the letter to negate one wound, or possibly even stay in the room and negate both wounds. If all you're interested in is moving on to the next scene, you really only need one success.

Now, after thinking about it a bit, I realized that this resolution mechanic is a perfect fit for a narrative-focused game. It might not be that good of a fit for something less narrative focused, though. So it might not be something I want to use in one of my own games, but it's still an interesting mechanic. Which got me thinking about how I might read up on various other systems and see if I could extract an interesting mechanic to use in a homebrew system.

Fudge is a system I've been eyeing for a while. It seems right up my alley, but I've never had a chance to play it. I was looking over the Fudge rules again and I was reminded of just how archaic they are. Fudge was meant to be similar to GURPS, but simpler and more streamlined. And it is. But compared to something like D&D 5e, it doesn't really look so streamlined anymore. As I was reading the rules, I came to the conclusion that perhaps Fudge isn't what I was looking for after all (though I could homebrew a version of Fudge that was, but at that point I might as well make a system from scratch). But there was one part of the rules that intrigued me. The wounding mechanics were almost identical to something I've posted on these very forums before. And I can't remember if I came up with it independently, or if I read Fudge first and it inspired me.

So what would be some other systems I could look into to steal their mechanics and cobble together a homebrew system? Preferably, I'd be looking for mechanics that are simple and elegant, easy to use and fast to run. I probably don't want to copy an entire subsystem, but the foundational mechanics for a subsystem might be worthy of inspiration.

[Saintheart]

From what I gather, the hideously- communicated but intuitively purposeful FATE system might be worth mining for this kind of stuff ...

[Vahnavoi]

What games other than tabletop roleplaying games have you played?

[Pauly]

I would strongly recommend against frankensteining a system from bits and pieces of other games. I’ve played enough of them to find it super annoying when the gears crunch when you’re shifting from one sub-system to another.

1) Look for a core mechanic that suits your main objective.

2) look at different ways to resolve probability. Some options include
1d(n) +/- modifiers.
Nd(n) +/- modifiers.
N variable d (instead of adding a +1 modifier you go from d6 to d8 or d8 to d10 and so on)
Dice pool.

3) look at success.
Binary
Binary + critical success/failure
Graded.

4) what can you use the die roll for.
Some systems are roll to hit, roll to damage, roll to save, roll for any additional effects.
Other systems can resolve multiple effects by having different colored die.

5) decide what is more important - the modifiers or the dice.

[Telonius]

Anyway, despite my misgivings, there's one aspect of the rules that intrigues me: the core resolution mechanic. When you attempt an action, you make a roll to generate a number of successes (called "raises"). To complete the action you are attempting, you'll need to spend a certain number of successes, but that's not all you can spend them on. Each action also comes with potential Consequences, negative effects that you can nullify by spending a success on them. An action can also open up Opportunities, some kind of extra bonus that likewise requires spending a success to take advantage of. The example used in the book was running out of a room that was on fire. Attempting to flee the room costs one success to carry out the action, comes with the consequences of receiving two wounds due to being burned (each of which can be negated by spending a success), and you also spot an important looking document about to be consumed by fire that you can grab on your way out.

What intrigues me about this mechanic is that it's not a strict pass/fail resolution. More or less, you get degrees of success, and then spend those like a currency to improve the situation. If you have four successes, then you can carry out the action "perfectly", i.e. you flee the room without getting burned and grabbing the document. (I believe you can also spend successes on additional actions, e.g. if you were being chased, you could topple a bookcase to block the door before you flee. So if you had more than four successes, you could find things to spend them on.) If you only have three successes, you can still "pass" the check, fleeing the room without taking damage, but you wouldn't grab the document. Or you could decide that grabbing the letter is worth more to you than preventing a single wound of damage. What's interesting is that this power is given to the player to make that choice. With only two successes, you can eat the two wounds and still flee with the letter, or give up the letter to negate one wound, or possibly even stay in the room and negate both wounds. If all you're interested in is moving on to the next scene, you really only need one success.

I've played around with an idea like this, but not on the micro level - more like on the macro level - for a "superhero" style game. The idea is that the characters are in totally-not-Ankh-Morpork, and have been tasked with being Golden Age-style superheroes. They'd encounter a reporter (a "Paladin of journalism"), a retired Bruce Wayne-ish elf (the first masked hero of town), a whole rogues' gallery, and so on. Each mystery would have a bunch of "victory points" to it. Fail enough, and the local "Daily Bugle" has its version of the stories believed, and the town becomes more hostile to the heroes (with mechanical and fluff effects) and more like Gotham on a bad day. Succeed enough, and the journalism Paladin (and local "Daily Planet") have their version believed, and the city gets friendlier, prettier, and happier.

I'd originally put the idea together for a 3.5 campaign. The rules could absolutely support it. But after looking around a bit, if I ever get this off the ground it'll be using the "Masks" RPG (runs on the Powered by the Apocalypse mechanic, not d20). Very definitely a rules-lite system, much more narrative-focused. I definitely think it's a better fit to the idea than standard D&D would be. (No experience with 5.0, so that may have changed).

[Quertus]

Well, OP, you opened with 7th sea, and explained the really good reason why its mindset is the best resolution mechanic I've encountered. This "Degrees of success, spend them as ye will", that turns action resolution into a conversation, is, well, optimal, IMO.

What more do you want?

Hmmm... the only other mechanic I can think of that might be anywhere near as interesting is the notion of luck / fate / hero points. Not just for rerolls (which I, personally, enjoy), but which also can be gained by suggesting additional difficulties, or spent for fortuitous circumstances.

"Can I get a Luck Point and have a hotdog vendor push his cart out in the street in front of me / have a Citizen about to fall off the building / now, while we're hiding, is when the faerie in my pocket wakes up?"

"Can I spend a Luck Point to have there be a manhole down this side street & the manhole cover be off / to have our prisoner be allergic to the ropes we tied them up with / to have it start raining?" (don't ask me how all those are advantageous)

This idea of a resource for Limited Player Authorship (both positive and negative) is kinda cool, IMO.

Not the way Fate does them, where it forces you to follow compels. But where the players choose to add reasonable complications to their existence.

[kyoryu]

From what I gather, the hideously- communicated but intuitively purposeful FATE system might be worth mining for this kind of stuff ...

So hideously communicated that a fan wrote a bunch of stuff about learning the system - which has become a go-to guide for learning it, and was even put in print.

https://bookofhanz.com/

Other systems I'd look at:

BRP
HERO/GURPS
Savage Worlds
PbtA
FitD
Hillfolk
Fiasco
Genesys
Pathfinder 2

[Yora]

I found the game that made me appreciate the most new ideas to be Apocalypse World. It goes out of its way to be hard to understand by presenting all its rules in its own weird slang, which is absolutely bad game design. But the underlying system is really quite brilliant once you manage to decipher it.

Blades in the Dark is much more accessible in its presentation, but also more conventional in its mechanics and procedures, which make it a bit less interesting from a design standpoint in my perspective.

Maybe Saga of the Icelanders might be a good middle ground. It's a game about playing a family of farmers in Iceland, getting into trouble with the neighbors. PCs can be the father of the family or his loyal companions, and as such be viking warriors, but other roles are his wife, the family slave, a child, and various other noncombatant. And being a viking family saga, there's probably going to be murder and violent betrayal. It's a very different approach to what an RPG can be than the typical adventurer party, and ir's based on the same interesting mechanics as Apocalypse World.

[Anonymouswizard]

Pretty much anything by Jenna Moran, particularly the Jenna-verse games (Nobilis, Chuubo's Marvelous Wish Granting Engine, and Glitch). They're amazing pieces of game design that perfectly emulate the world's and stories they're intended to.

As a plus they'll also completely restore your faith in diceless roleplaying, as well as high powered games.

This is how you write 'this is the sorts of things you can do with a stat'. Not always the most clear, Nobilis has a recurring issue with Wounds systems and its third edition had a confusing mortal actions system, but generally good. That mortal actions system is still worth having a look at because it does run on 'do you succeed or fail' but 'how will this affect your life', but do yourself a favour and check out the better presented implementation in CMWGE. But they're great and innovative games, I love XP Actions/Spotlights and Emoting as a way of modelling story beats.

An additional thing I'd like to note is that one of them, Chuubo's Marvelous Wish Granting Engine, is 500 pages of solid rules. It's also a complete and utter demolishment of the idea that combat needs lots of rules, because it doesn't get them whereas property roleplaying slice of life stories and character development does. Character's in CMWGE fight, but they fight in order to do things. You don't engage in combat because it's what the game's about, but because it's in the way of your intention of 'I must pet the kitten'.

[Greywander]

From what I gather, the hideously- communicated but intuitively purposeful FATE system might be worth mining for this kind of stuff ...

Eh... I'd rather not have anything to do with Fate. Evil Hat has made it clear that "my kind" aren't welcome at their table. Though I suppose stealing from your enemies is fair play.

What games other than tabletop roleplaying games have you played?

Video games? Uh, Dark Souls, Civilization, Age of Empires, World of Warcraft, Zelda, Mario, Pokemon... we'd be here all day if I had to list everything. Maybe you could narrow down the question a bit?

I would strongly recommend against frankensteining a system from bits and pieces of other games. I’ve played enough of them to find it super annoying when the gears crunch when you’re shifting from one sub-system to another.

Oh, I agree. I have no intention of copying a mechanic verbatim and shoehorning it into a system with no proper integration. Mostly, I'm looking for inspiration that would allow me to create mechanics that are similar, but adapted for the system I'd be using them in. And yes, creating a solid core resolution mechanic is the most important thing, and then everything else would be built around that. Not every elegant mechanic would be useful, since there might not be a way to adapt it to the system without losing that elegance, but a broader awareness of the different types of mechanics one could use will help in developing original mechanics. For example, if all you've ever played is D&D, then it might not even occur to you to try a roll-under mechanic; roll + stat vs. DC is all you know.

Well, OP, you opened with 7th sea, and explained the really good reason why its mindset is the best resolution mechanic I've encountered. This "Degrees of success, spend them as ye will", that turns action resolution into a conversation, is, well, optimal, IMO.

I think the mechanic fits a narrative game really well, but I'm not certain it will adapt well to non-narrative-focused games. Out of the Narrativist-Gamist-Simulationist triad (which I understand isn't perfect), I'd say I'm heavy into Simulation, and fairly strong on Game, but weak on Narrative. So I'm not really interested in developing a narrative-focused game, because that's not really what I find as fun. I'm more about emergent puzzle solving and Combat as War.

All that said, I'll investigate if this mechanic can be adapted for use in a non-narrative-focused game. I do like the tactical value in choosing how to spend a limited number of successes to achieve the goals of an action while mitigating consequences. I do worry that it could slow the game down if used for every roll, though. But maybe that's an opportunity to point out that not everything should need a roll; if it's not impossible and there's no meaningful consequences, then why bother rolling?

What more do you want?

Well, a strong core resolution mechanic is the most important thing, but there are also any number of subsystems. I've already mentioned Fudge's wound system. There are also things like how actions and turns are handled during combat, as well as various other subsystems like social combat, social influence and intrigue, crafting/economy, sailing, and so on. Some systems might also have really interesting magic subsystems, which tend to intersect with the base rules but otherwise be virtually independent.

Other systems I'd look at:

BRP
HERO/GURPS
Savage Worlds
PbtA
FitD
Hillfolk
Fiasco
Genesys
Pathfinder 2

Apocalypse World
Blades in the Dark
Saga of the Icelanders

Pretty much anything by Jenna Moran, particularly the Jenna-verse games (Nobilis, Chuubo's Marvelous Wish Granting Engine, and Glitch).

I don't know when I'll have time to read over all of these, so I'll need to prioritize, but thanks for the suggestions. This should keep me busy for a while. I've already looked a bit at GURPS and Savage Worlds, so I have a bit of a head start.

[Vahnavoi]

Video games? Uh, Dark Souls, Civilization, Age of Empires, World of Warcraft, Zelda, Mario, Pokemon... we'd be here all day if I had to list everything. Maybe you could narrow down the question a bit?

The question is purposefully broad to see what you answer. I would advice you to go even broader and list card games and board games also.

To comment on the named examples:

Dark Souls (at least the first one) is what an AD&D game with infinite resurrects would look like in third person. There aren't any really new ideas to plunder there as far as tabletop games go. The one thing that's rare for tabletop games is minor part of Dark Souls gameplay: codified ability for players playing the same scenario to draw messages on the map and thus give information to players they might not even know. Trivial to do in a convention setting, much harder if you are making a system for isolated groups playing isolated games.

Zelda too is D&D adjacent - you explore the overworld, delve into dungeons, use new items and magic found in dungeons to find new routes to progress. Lots of great samples for puzzles and locations, not so much for a system. Breath of the Wild is something of an exception, simply because it does open world adventure particularly well and you can mine it for ideas for how to give players information and directions in a large scale map-based game.

Civilization 6 is worth looking at to see how the computer-controlled nation leaders deal with grievances, other players supporting or transgressing their agendas, voting in the world council etc.. These kind of interactions become important if you want your system to include high level strategic and diplomatic scenarios. Diplomatic visibility and gossip systems are also worth looking at, for ideas on how indirect flows of information might reach player characters.

Pokemon is mostly useful if you want to involve rock-paper-scissors-type dynamics somewhere in your system. Look at higher level analysis of competitive Pokemon (etc.) to see how the different pieces fit together and what kind of gameplay and strategy they promote.

Mario has some ingenious scenario design and ideas for how different areas can be connected to each other, but not much on the system level you could copy to tabletop.

[Telok]

Exalted & DtD49k7e have versions of a "build your own magical martial arts moves" subsystems. Champions, at lesat 3e, had a "build a martial arts package" bit (since it was all really just different boosts/mods to basic attacks having a themed "style" was just a points cost discount really).

The Warhammer franchise has a "dangerous magic" system in various forms. Ars Magica has an interesting take on magic ability progression.

What's the game with the escalation die? That was an interesting mechanic with possibilities. The 2d20 systems, Conan in particular, had a "momentum & danger" sort of metacurrency-like system the players & GM bartered back & forth for rerolls & boosts.

There are some systems that let you take things like complications & hinderances on a character then give you extra xp or metacurrency for choosing to invoke them.

An old FASA rpg named Legionnaire, the Mechwarrior rpg, and Traveller (just off the top of my head) had lifepath character generation. I always wanted some game to do a guided/semi-random/"choose your own" lifepath character generation to be able to work in the built in "fits the game genera/style" character background while placating the people who are deathly allergic to any form of randomization in char gen. As a plus, if done well, it means you don't need any previous system knowledge to create a character and can avoid trap options for new players.

Several systems integrate stunts & action description into the mechanics, giving people bonuses for going beyond "move, attack that one, <roll> hit, <roll> X damage" and other boring **** like that.

[Telonius]

Video games? Uh, Dark Souls, Civilization, Age of Empires, World of Warcraft, Zelda, Mario, Pokemon... we'd be here all day if I had to list everything. Maybe you could narrow down the question a bit?

Dwarf Fortress. Though I'm not sure how portable the "Losing is fun!" thing would be for D&D. (Maybe in a Horror campaign...?)

[Vahnavoi]

"Losing is FUN!" as a mindset is easily portable to tabletop - there is no victory condition, just an open-ended situation that keeps getting harder until you either get bored or make a mistake and die. The game mechanics of Dwarf Fortress are too heavy to do by hand, but nothing about the subject matter is foreign to tabletop.

[NichG]

I think there's a lot of potential to generalizing that 7th Sea approach to the idea that rather than asking 'does this succeed?', you pivot a system to entirely be about asking 'how much does this cost, can you pay the cost, and what are the consequences?' that would be compatible with a more fine-grained mindset. These days I tend to run stealth as more of a alertness HP pool than a binary 'spotted/not spotted' thing - spend a base of one stealth point to sneak across an open area when there are people nearby, two if it's being actively monitored; if they have perception skills/buffs, the cost will be higher but you won't know until it comes time to pay it, etc. You could just as well have investment in lockpicking be 'the number of times at a particular location where you can choose to auto-succeed at picking a (base level) lock despite a failed roll' rather than modifying the probabilities in that roll, investment in social skills tell you 'the number of dirty secrets you managed to dig up before the meeting' or 'the number of lies you can get away with before you're caught out' rather than probabilities of those things, investment in a defensive skill being the number of attack-points worth of attack you can choose to auto-dodge, investment in resilience tells you the number of levels of status effects you can automatically shrug off in a particular combat, etc. All of course as long as the pool associated with each skill hasn't been depleted yet.

Exalted has some of that with perfect defense / perfect offense type things, and my impression is that people generally criticize those aspects rather than find them good, but I think part of that is that those are placed like cherries on top of a charm progression so it becomes something like a feat tax. Whereas if everything in the system worked according to some kind of bidding or spending from pools to determine whether stuff lands or not (especially if the relationship between chosen attack and defense modifies the cost efficiency), I think it would resolve that issue.

[Easy e]

Before you try to make your own system, there are absolutely two things you MUST do:

1. Read and play a ton of game systems from different genres and styles

2. Write out your design goals and guidelines

Then, start putting words on a page somewhere, and you are off......

[Satinavian]

I will recommend SIFRP as i have plundered it for mechanical ideas several times myself.

[olskool]

I've long wanted to design an original system, but it's a tough thing to do when you're not familiar with a broad set of systems.

Recently, my sister offered to DM a game of 7th Sea, a game she kickstarted but hasn't had a chance to play yet. (We haven't started yet, so I might be misunderstanding some of the rules here.) I was reading over the rules and I can tell this game isn't for me. It's highly narrative focused, and to call it "rules-lite" would be an understatement. You'd think ship customization would get a dedicated subsystem as complex as D&D's magic system, but nope, all ships are identical; doesn't matter if you have a sloop or a man'o'war (you can get upgrades for your ship, but the type of ship is entirely cosmetic). Firearms have special rules in that they do extra damage, but there's no equipment section so I'm not sure how one is meant to procur them. Can I... can I just start with a dozen pistols?

Anyway, despite my misgivings, there's one aspect of the rules that intrigues me: the core resolution mechanic. When you attempt an action, you make a roll to generate a number of successes (called "raises"). To complete the action you are attempting, you'll need to spend a certain number of successes, but that's not all you can spend them on. Each action also comes with potential Consequences, negative effects that you can nullify by spending a success on them. An action can also open up Opportunities, some kind of extra bonus that likewise requires spending a success to take advantage of. The example used in the book was running out of a room that was on fire. Attempting to flee the room costs one success to carry out the action, comes with the consequences of receiving two wounds due to being burned (each of which can be negated by spending a success), and you also spot an important looking document about to be consumed by fire that you can grab on your way out.

What intrigues me about this mechanic is that it's not a strict pass/fail resolution. More or less, you get degrees of success, and then spend those like a currency to improve the situation. If you have four successes, then you can carry out the action "perfectly", i.e. you flee the room without getting burned and grabbing the document. (I believe you can also spend successes on additional actions, e.g. if you were being chased, you could topple a bookcase to block the door before you flee. So if you had more than four successes, you could find things to spend them on.) If you only have three successes, you can still "pass" the check, fleeing the room without taking damage, but you wouldn't grab the document. Or you could decide that grabbing the letter is worth more to you than preventing a single wound of damage. What's interesting is that this power is given to the player to make that choice. With only two successes, you can eat the two wounds and still flee with the letter, or give up the letter to negate one wound, or possibly even stay in the room and negate both wounds. If all you're interested in is moving on to the next scene, you really only need one success.

Now, after thinking about it a bit, I realized that this resolution mechanic is a perfect fit for a narrative-focused game. It might not be that good of a fit for something less narrative focused, though. So it might not be something I want to use in one of my own games, but it's still an interesting mechanic. Which got me thinking about how I might read up on various other systems and see if I could extract an interesting mechanic to use in a homebrew system.

Fudge is a system I've been eyeing for a while. It seems right up my alley, but I've never had a chance to play it. I was looking over the Fudge rules again and I was reminded of just how archaic they are. Fudge was meant to be similar to GURPS, but simpler and more streamlined. And it is. But compared to something like D&D 5e, it doesn't really look so streamlined anymore. As I was reading the rules, I came to the conclusion that perhaps Fudge isn't what I was looking for after all (though I could homebrew a version of Fudge that was, but at that point I might as well make a system from scratch). But there was one part of the rules that intrigued me. The wounding mechanics were almost identical to something I've posted on these very forums before. And I can't remember if I came up with it independently, or if I read Fudge first and it inspired me.

So what would be some other systems I could look into to steal their mechanics and cobble together a homebrew system? Preferably, I'd be looking for mechanics that are simple and elegant, easy to use and fast to run. I probably don't want to copy an entire subsystem, but the foundational mechanics for a subsystem might be worthy of inspiration.

Rather than hit you with a list of 30 different games, I'll focus on the Mechanic you just mentioned... The Degrees of Success mechanic.

#1: The first MODERN one that comes to mind is Modiphous Games 2D20 System. In this system, you roll two or more D20s and are attempting to roll UNDER a given number based on one of your Characteristics modified by any factors the DM gives you. Each D20 that rolls under this number is a "Success." Each Success after the number of Successes you need to perform a task (normally from 1 to 4) generates a point of "MOMENTUM." You may also have another number called a FOCUS. Think of this as a "skill level" in 2D20. IF you roll UNDER YOUR FOCUS, you automatically generate TWO SUCCESSES with that D20 roll. Momentum can be "spent" on all kinds of special maneuvers and effects. You can even spend Momentum to get extra D20s to roll.

#2: The next MODERN game that gives you a number of successes by dice roll would be Free League's YEAR ZERO Engine. In this system, you use ALL the polyhedral dice but normally start with a D6. Your Attributes are ranked by Die Size. Thus, your STR might be, D6, D8, D10, or even D12. Bonuses and penalties move your die size up or down. So a D6 might bump up to a D8 or even D10. However, It couldn't bump down to a D4 (see Success levels below for why). In the versions I played, you would receive a Die to roll for... Attribute (always), Skill (if you have a relevant skill), and even for Equipment (if you have a good piece of equipment). Thus you would be rolling at least 2 and sometimes 3 dice. Any roll of 6 was a Success and each Die can succeed. Rolls of 8, or 10, or 12 on a die would net you extra successes (at one per step), So rolling a 12 would net you 4 Successes on THAT die. Extra Successes could be spent on Special Effects.

#3: The Classic Dice Pool Mechanic as shown in the latest edition of Shadowrun and Star Wars. You roll a number of D6s and any roll of a 6 (and in some games 5 or 6) is a Success. You then tally up the Successes.

#4 A "Homebrewed" version of the FIRST/SECOND Edition Shadowrun. In the original Shadowrun, you had a Target Number that could run from 2 to 10. You would reroll any 6 and add it to a 6 to get the higher numbers. In addition, you would roll multiple dice to score multiple Successes. In addition to the Target Number, every Task had a threshold for Success. This Threshold was the NUMBER OF SUCCESSES the PC HAD to roll to Succeed. If a task required 3 Successes, then you needed to roll for 3 Successes to perform that task! In the late 80s, I modded this. I now set Target numbers at 2 to 9 BUT we now rolled D10s instead of D6s to hit that target number. White Wolf would adopt this system as well for their Worlds of Darkness games (Vampire, Magic, etc...). So in our Homebrewed Shadowrun 2e, we would roll a number of D10s against a target number of from 2 to 9. On any roll of 10, that Die would "explode," meaning you would get ANOTHER D10 to roll for a Success. This exploding mechanic was straight out of Flying Buffalo's Tunnels & Trolls RPG. We set the number of Successes needed to a color code to match the Matrix rules. So we had...
Green = 1 Success
Yellow = 2 Successes
Orange = 3 Successes
Red = 4 Successes
Black = 5 Successes

So IF I told you: "To pick that lock is a 6 Yellow Task..." You would instantly know you needed to roll a 6 or more on D10 and you needed 2 or more Successes. It was a VERY FAST method of setting Task Difficulty and gave you a great deal of Flexibility. The flexibility was impressive.
For example, a Task could be a 3 Red (an easy roll but you need a lot of Successes), or a Task could be an 8 Green (a hard roll but only 1 Success needed). This greatly simplified Shadowrun 2e.

Those are the Dice Pool Mechance games I'm familiar with. Other games to check out are...

Green Ronan's FANTASY AGE 3D6 roll-over system (like 5e).
The Design Mechanism's MYTHRAS and its cheaper cousin Mongoose Publishings LEGEND and their Percentile systems.
Mongoose TRAVELLER and its 2D6 resolution system.
GDWs (now Far Future Enterprises) Twilight2000 V2.2 D20 roll-under system.

Each game has its own charm and you won't be lacking for ideas.

[Pauly]

GURPS has a very good and often copied character creation system, where you create the background of the character which then translates into skills and abilities. It also has the advantage/disadvantage system of boosting your character at the cost of mechanically enforced downsides.

[Psyren]

Dwarf Fortress. Though I'm not sure how portable the "Losing is fun!" thing would be for D&D. (Maybe in a Horror campaign...?)

"Losing is FUN!" as a mindset is easily portable to tabletop - there is no victory condition, just an open-ended situation that keeps getting harder until you either get bored or make a mistake and die. The game mechanics of Dwarf Fortress are too heavy to do by hand, but nothing about the subject matter is foreign to tabletop.

"Losing is fun" sums up a lot of my Cthulhu experiences...

[SimonMoon6]

I'll just discuss DCHRPG (Mayfair's DC Heroes RPG) and TORG.

1. In DCHRPG, every action that involves rolling dice for success or failure works in exactly the same way. Are you attacking? Are you using a skill, such as Charisma or Gadgetry? Everything involves the same kind of die roll.

You have two stats you're attacking with and the opposition has two stats they're defending with. In physical combat, we're talking your DEX (to hit the opponent), your STR (to damage the opponent), the opponent's DEX (to avoid getting hit), and the opponent's BODY (to try to avoid being hurt). Every action has a similar set of four stats.

Then, you roll on a table, which is in two parts. The first part of the table tells you if you succeed (and how well). The second part translates that into damage (or amount of success for other actions).

It's a pretty simple system.

2. TORG is fairly similar (but without the table) but what I want to mention is a unique aspect to TORG that I haven't seen in other games. In addition to rolling dice for success and stuff, there's also a deck of cards used in combat or other stressful situations. The deck has two modes to it... is this a fairly normal part of the adventure or is it a really dramatic part of the adventure? Things work differently in the dramatic parts of the adventure (often to the detriment of the PCs).

Every turn, a new card is flipped up, with various modifiers to the combat (or whatever you're doing). Perhaps the villains get initiative this turn. Perhaps the heroes are stunned or stymied or face some other setback. Perhaps the heroes get a bonus to using taunt. Perhaps your attempt to disarm the bomb has a chance to advance successfully this turn (or maybe it doesn't).

This adds a new and unpredictable element to every combat and makes dramatic scenes more dramatic as the PCs are more likely to be screwed over by the cards.

[Easy e]

The answer to the OP is any system you can get your hands on and eye balls to read is a good system to plunder for ideas.

To apply this to wargame design for a moment. I think the Osprey book On the Seven Seas is not a good wargame. I have no interest in playing it. However, it has some mechanics in there that I like. If I had never gotten my hands on it and read it, I would never have known about the one mechanic I like in it.

[Goobahfish]

I have played:
WHQ (somewhere between a board game and an RPG)
D&D-esqe: Star Wars, Spycraft, Modern, Classic, Warcraft
LOT5R
Warhammer RPG
Necromunda, Mordheim (I mention these as they are RPG-lite skirm games)
Inquisitor
Pathfinder
Advanced Fighting Fantasy
One-Deck Dungeon (not even really an RPG as much as a board game)

I have also built an entire RPG (D&D adjacent) which I run with two groups.

So:

Part 1: What are you trying to model?
From the sounds of it... a dice-heavy game (i.e. things are resolved mechanically). This is entirely sensible. The narrative-based version of roleplaying games is usually best left to the GM's judgement.

Part 2: What are you trying to model? As in... mechanically?
Honestly D&D suffers from an attempt to unify everything into a D20 pass/fail paradigm. It works pretty well for combat... for swords, fireballs etc. It handles CC spells like hold person, cause fear less well (they become save or die). It handles non-combat encounters very poorly. Stealth or die. Jump or die. Disguise or die. Swim or die. Intimidate they either cower or they don't. Only a good GM will save D&D from its 2nd pillar. D&D also loves its random little resource pools (spell slots, ki, superiority dice, rage, blade dances, sorcery points). Yet they shy away from anything except HP, where there is little nuance.

Part 3: What is there mechanically and what is it broadly good for.
I figured I might save you some time.

Dice: (Whoa a game with dice)
* Can resolve binary choices (XDY vs DC, sum dice, compare to DC) - D&D and everyone else
* Can resolve levels of success (XDY vs DC, each die above a target is a kind of success) - LOT5R RPG was in this vein
* Can resolve resolve graded success (XDY vs Pool, objectives/creatures have a number which is reduced/added to by dice rolls until it reaches some target) - think crafting, hit point pools etc
* The above can also be done with custom dice (random symbols)
* Use dice of a certain type/colour to cover a box to defeat a challenge (see One Deck Dungeon)

I've seen a lot of variation on dice. D20 is a uniform distribution, 2D10, 2D20, 2D6 etc is a more normal distribution. Roll lots of D6s/D10s to achieve some goal. I think the mistake most games make is to try to pick one and use it uniformly. D&D has two dice mechanics. DC's and damage. Adding a third for ability checks wouldn't be a bridge too far.

Pools: (Almost all games have this)
* Hit points!
* Morale
* Special power costs (ki, mana, spell slots)
* Some kind of action currency? (Action Dice, Inspiration, Grit etc)

D&D has this for... HP and class resources. Other games have morale. Some have sanity. This is where your setting starts impinging on your ruleset and usually quite heavily. In Cthulu games, being mad is important enough that every character has it. Star Wars has force points and light-side/dark-side points (or at least one version did).

Characteristics: (Almost all games have this)
* Modifying challenge DCs
* Making characters distinct

A warning. Lots of games use English words to make their stats. I suggest you think carefully about mechanics before trying to find names here. Most games have these. LOT5R had Air/Earth/Fire/Water/Void as stats which then translated to speed, toughness etc. Totally weird. D&D's stats are pretty awful but will be with us for all time. Setting will also have a big impact here. Luck? The Force? Attacks?

Skills
* Broad (basically combat/magic/etc)
* Narrow (fishing, fire magic, daggers)
* Flexible (spend how you will, 3.5E)
* Fixed (Proficiency in 5E)

Special Actions
* Flexible. (You have points, spend them)
* Skill-tied (if you have the skill you can take the special ability)
* Coupled (D&D classes are highly coupled abilities... you a druid you have spell casting and wild shape. BOTH. IT MUST BE BOTH!)

States
* Pathfinder/2... what were you thinking
* 5E... have disadvantage

Keep these either very simple, few or intuitive.

Card decks
* Events
* Random outcomes that want to be non-repetitive within a single game
A lot of work but superior to look-up tables as they are a non-replaced randomness and are easily added to/customised.

Look-up tables
* Treasure... except its not really good for this
* Events
* Actions
Unless these are really common, they usually grind a game to a halt. Use with caution. GW games are big offenders here with games like Mordheim, Gorka Morka, WHQ all leaning heavily into tables to generate content, injuries, treasure etc.

Actions
* 3 actions/turn (Pathfinder 2)
* Move, Attack, Free (WHQ, D&D)
* 2 actions/turn (Spycraft, Starwars)
* Team turns (GW games)
* Initiative (WHQ, D&D, LOT5R)
* Action dice with complex actions

This will be your bread and butter. How many actions per turn/player? This one is probably the most interesting to play with. I mentioned elsewhere I think the 7th sea mechanic is interesting but there are a few ways you can play with it. Do you have control over how many dice you roll (perhaps there is a penalty). Do you assign dice before success or after?

[Yakk]

One Roll Engine has some neat mechanics. Roll pools of d10s, and look for matching sets. The number of matches (width) and the value (height) both have impact.

Then add in fancy dice, like dice you set before you roll, dice you set after you roll, and dice that can only be used to make a success wider. You could also have dice that can be used to move a die up or down.

You could imagine a system where you roll your maneuver dice and your attack dice, and any match that contains a maneuver can be used defensively, an attack used offensively, and both can be used either way. The width is how fast it is, the height is how big it is.

...

Another fun one to mine is Dungeon World. The DM-facing mechanics are very interesting.

[Beleriphon]

Rather than hit you with a list of 30 different games, I'll focus on the Mechanic you just mentioned... The Degrees of Success mechanic.

#1: The first MODERN one that comes to mind is Modiphous Games 2D20 System. In this system, you roll two or more D20s and are attempting to roll UNDER a given number based on one of your Characteristics modified by any factors the DM gives you. Each D20 that rolls under this number is a "Success." Each Success after the number of Successes you need to perform a task (normally from 1 to 4) generates a point of "MOMENTUM." You may also have another number called a FOCUS. Think of this as a "skill level" in 2D20. IF you roll UNDER YOUR FOCUS, you automatically generate TWO SUCCESSES with that D20 roll. Momentum can be "spent" on all kinds of special maneuvers and effects. You can even spend Momentum to get extra D20s to roll.

A very important caveat that Modiphious games use is they are best described as Genre Story Simulators. Star Trek Adventures is basically a Star Trek Episode simulator, not a Star Trek Universe simulator, as such the 2d20 system needs to take into account the the Momentum and Threat (GM Momentum built by the players) pools.

[Kioku]

I would have to say that Shadowrun 4e / 5e has the single best magic system I've seen in a game, and the best base mechanics for rolling. Certainly an option to look into for homebrew ideas.

[Xervous]

I would have to say that Shadowrun 4e / 5e has the single best magic system I've seen in a game, and the best base mechanics for rolling. Certainly an option to look into for homebrew ideas.

While I greatly enjoy some Shadowrun systems and agree the probability curves for the base mechanic are awesome, the combined tedium of all system rules weighs down every single casting attempt. When looking here for inspiration I had more success splitting spellcasting into a 0 drain default casting formula, then tacking on spell upgrades that bring a risk of drain.

[Anonymouswizard]

I would have to say that Shadowrun 4e / 5e has the single best magic system I've seen in a game, and the best base mechanics for rolling. Certainly an option to look into for homebrew ideas.

Honestly Anarchy is the only version of Shadowrun I could handle anymore, and even then I'd want to combine Edge with Plot Points.


Savage Worlds is also interesting, even if only in terms of how much you can cut down a system (it is, by my understanding, a heavy simplification of the original Deadlands rules). Deadlands might also be worth looking at, if only for things such as the character creation and Huckster magic (which both rely on standard playing cards).

[Xervous]

On the Shadowrun side of things, 5e has a lot of DON’T DO THESE things.

Wireless bonuses
Character critical gear (cyberdecks) costing a ton and being destructible (if it’s crucial and can break, maybe don’t make it cost so much).
Limits

And corporate embezzlement that loses you all your good writers and editors.

[Anonymouswizard]

On the Shadowrun side of things, 5e has a lot of DON’T DO THESE things.

Wireless bonuses
Character critical gear (cyberdecks) costing a ton and being destructible (if it’s crucial and can break, maybe don’t make it cost so much).
Limits

And corporate embezzlement that loses you all your good writers and editors.

On cyberdecks, a good Deckmeister should be able to fix one relatively cheap. You did remember to buy one as a Contact, right?

But yeah, I feel like 5e had the price of hacking gear skyrocket to make Technomancers more viable. Although the one built in the character creation example is hilariously bad. Never remembered to use wireless bonuses or Limits (not sure anybody ever hit one), and the behind the scenes issues are shocking.

I hear that 6e has it's own host is issues. I don't really care, I significantly prefer Anarchy to full blown Shadowrun because it gets rid of the Nuyen counting and simplifies augmentations.