4 of the Most Common TTRPG Dice Systems

There are so many great RPG systems out there - here are some examples of the most common dice mechanics!

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Special thanks to James Arnold Taylor and Gabor Vida

[Ishpeck]

This is an important conversation to have. System _does_ matter and talking about their impact on game-play/narrative is vital for the artistry of RPG's to truly unfold.

[magiuspendragon]

It's worth pointing out, d20 roll under is basically a the same as a. d100 system, in terms of how the probabilities work out -- One of your cons was about the swinginess of d20, because it's a uniform probabilities. d20 roll under -- if you apply modifiers to the target number instead and then multiply by 5 you'll get the probability for a d100.

[jonathanbaago]

My favorite to date is Forbidden Lands dice pool. It works well, its quick and deadly and flavorful in combat and its very easy to work in with and learn newcomers

[teya]

Something I’ve only seen in Neoclassical Geek Revival but think is absolutely great is kind of an extension of Stars Without Numbers. What dice system you use depends on your character’s stress level. If you’re calm and everything is going right for you add a flat +10 to your modifier, when something first goes wrong, you fail a check or take damage you’re shifted up to 3d6 and when you’re totally panicked and don’t feel at all in control of the situation you roll 1d20. You need to get back to somewhere safe and get a full rest to go back down to calm. Playing that system really got me to appreciate how big a difference die mechanics can make to the tension of a moment in game.

[cajunmitch]

Savage Worlds, and games with changing die types, are called "Dice Ladder" systems.

[billn]

Thank you for increasing exposure to other systems! I get a little frustrated when discussions about "other than D&D" only involve D&D clones.
I particularly love the Genesys dice pool system, Free League's Year Zero engine, and the Modiphius 2D20 systems.

[StepBackHistory]

Controversial take, but I like how the odds in dice pools are messy. It lets you see chances in the sort of vague way that you would in assessing risk in a real situation. But admittedly I am in love with the Blades in the Dark system.

[joaosevero]

I am so glad to hear what you said at the very end of the D20 section, about the system not emphasizing the characters skills so much. I always felt that and it is exactly what prompted me to look for and eventually try to develop something else.
I always felt that in the D20 system whatever skills and bonuses your character has, they all pale in comparison to a single dice roll.

[luciussvartwulf]

Super happy to see you mention WEG Star Wars system (the best SW rpg I have ever played). WEG deserves far more loves for their system than they got, and a big bonus is that their "Generic" editions (Space, Adventure, Fantasy) are all free online, which is a great bonus for getting players into a game, while being one of the most flexible systems out there for running any type of adventure.

[melinnamba]

I love dice pool systems. Particularly 10 d10 systems. For one thing, as you said, it's fun when you get to roll a fistful of dice. And for another I also feel like it represents skill development really nicely. In the beginning when you only have 1 or 2 dice the results are more chaotic, like when you're in that phase of beginners luck and not quite grasping it yet. As you get to add dice your skills become more reliable. I really love the feel of this type of skill progression.

[davewilson]

D20 is effectively percentiles in 5% chunks. Both are just as swingy, but interestingly all the implementations seem to have little to no overlap.

[mata]

Earth Dawn from the 90's to its most current reincarnation uses an unique system. It uses steps. The skilled you are, the more steps you have. Each step # has its own dice you throw. From step 1 [d2] to step 37 [2d20 d12 2d6] or even more steps.

[thevilside]

It would be nice to have a series of videos similar to this one outlining other mechanics of rpgs that are done differently: injury and pain, fear and madness, equipment load etc...

[Seldinor]

Silhouette from Dream Pod 9 has a great system that pretty much no one knows about and it was used in the TTRPGs Heavy Gear and Jovian Chronicles.

The system uses D6s (but it was designed for D8s, and works better that way, but "marketing" decided D6 was the way to go) and it's a pretty nice system:
- You have a Dice Pool equal to your skill level. Level 1 is apprentice, 2 is Journeyman, 3 Master (4-5 are pretty rare and legendary). Lets Say you have Guns 3, so you throw 3D8.
- You check the higher number in that throw. If I got 3, 5, and 7 you only got a 7.
- You add your Atribute modifier. Standard is +0, abover average +1, good is +2. Lets say you have Agility +2, so 7+2=9 you got a 9!
- You compare that to the CD, usually it is a 5 and it can be modified by things like being wounded, range, etc. You can also do opposing checks, if your enemy knows you are shooting him he can Dodge. Let's say he has Dodge 2+1, he throws a 3 and 5, so he got a 5+1=6. He was hit.
- If you are calculating damage, you Multiply the Damage of the Weapon (x15 a 9 mm pistol) by the exceeding number. In this case 9 Gun - 6 Dodge = 3x15 = 45 damage. It has a Wound condition system, so 15 is Superficial Wound., 30 a Grave Wound and 60 Death. We got him for 45, so he has a Grave Wound, -2 on all actions. He dies on -5.

The only 2 things to know aside from this are the following:
- Extra 8s add +1 to the sucess. If I got a 3, 8 and 8 in my Guns 3+2 I have a 8+1+2=11. This is a great feature, because you cannot get absurdly high sucesses like in other systems, its very hard to get over 10 in a throw.
- You can only get a Fumble on all 1s on the throw. If I have Guns 3 I have to throw 1, 1, 1 to fumble. This is also amazing because the higher your skill the more difficult is to fumble. Level 1 is one in eight, happens a lot: you are an apprentice and it shows. Level 2 is really hard to get Snake Eyes. Level 3 I have never seen it, honestly, but I guess it can happen.

It is a really fast, small pool dice system, that can be used in any setting with little effort and seems pretty realistic. It's not great for heroics, but for historical RPGs or tactical ones like Heavy Gear and Jovian Chronicles it shines.

[K_E_Robin]

My personal favorite tool for learning about probabilities of different dice types, pools and mods is Anydice.

I use it to check the chance of succeeding in my own system.

[ddcardo]

I had a small who used a homebrew dice curve system for stat checks in ADnD. This was a while ago. You used d6s . The goal was to role less than your stat on the d6 alotted. The more difficult the check, the more dice you had to use.

[justinsinke]

Information like this needs to get out more. I have found it borderline depressing trying to get folks to understand systems that aren't D&D and they struggle because they're looking for parallels to D&D (made even more confusing for them when it's not even a D20 system) that aren't there, with questions like "how do I determine my AC" or "what's my attack roll modifier" in a system that doesn't use those concepts, or at least not in the same way D&D does, and they end up trying to force a square peg through a round hole trying desperately to try and find the parallels to find an ease of familiarity that just isn't there. It often feels like if they're not rolling a d20, they can't fathom how the system even functions because using a d20 is just how TTRPGs function in their minds. It makes it really hard to teach someone when the first lesson has to be reiterating several times how this isn't a d20 system and that, yes, there are systems other than the d20 systems that are still TTRPGs.

[michaelconnor]

The best balanced Dice pool system I have seen, is Silhouette by Dream Pod 9.

[frankb]

Some of my favorite old games are based on D10 systems (Ars Magica, Cyberpunk 2020, etc.). They basically function like D20 systems but count less on dumb luck as the range of randomness is only 10 instead of 20.

[NefariousKoel]

Dice Pools generally have another advantage I like. Less die roll modifiers to add or subtract from your die rolls. You often don't have to track a bunch of minuses and pluses for various things. Just count the number of successful dice and compare to the amount of successes the GM stipulated for success. Or, in some systems you just add or remove an amount of dice from your pool, beforehand, regarding bonuses or penalties. Cuts down on the math and DRMs at the table.

I also rather like that you only get a vague idea how easy a test will be with dice pools. Because when I'm preparing to do something difficult, I don't normally think to myself, "I have a 65 percent (or 13 out of 20) chance of succeeding at this." Yet you still get vague idea after becoming accustomed to the dice pool system you're using, depending on your character's skill & ability.