I’ve been on a big tabletop RPG kick recently, partially do to discovering a variety of interesting indie TRPGs, partially due to discovering a few excellent TRPG podcasts and YouTube channels, and mostly due to my personal gaming group meeting with far greater consistency than before. Whatever the reason, this surge in interest has led to a resulting surge in tabletop RPG design.
Specifically, I’m working on two games. The first, Blackmarked, I’ve written about before on this blog. As a quick refresher, it’s a quick and brutal low-fantasy game that’s equal parts Dark Souls and Dishonored. The second game is a newer project of mine called Asphyxia. This game is set in a far-flung sci-fi future, and centers on a party of special agents who get sent in by corporations to perform missions in a quarantined colony.
In my mind, the single most important part of any tabletop RPG is the central dice mechanic. This mechanic will be spun and remixed several ways within the rules to fit certain contexts (skill checks with no ranks in the skill, contested checks, etc.), but this dice mechanic will basically play a part in every mechanic of the game.
Despite this, people don’t give as much thought towards these central dice mechanics as they should. Many people, whose experience with tabletop RPG experience doesn’t extend much further past D&D, assume there’s basically one mode: roll some dice, add some of your numbers to it, and see if the result is bigger than the bad number. There’s nothing wrong with this, but it’s hardly the end-all of mechanics. In fact, looking at this mechanic shows how tailor-made it is for D&D specifically.
Think of it this way: D&D specifically has players roll a twenty-sided die, add their positive modifiers to it, and try to beat some target number. The thing about a d20 is that, as far as dice go, its results have an extremely wide range. There are twenty possible results, and each of them has equal probability of coming up. This works well with the central motifs of D&D: you’re supposed to play big, dumb heroes, and to tell epic stories, you want epic victory and miserable defeat to be relatively common occurrences. Given that rolling a 1 is automatic failure, and rolling a 20 is automatic success, this dice system ensures that even the most epic and ridiculous feats are always at least 5% possible.
What if we didn’t want a game full of epic successes and dismal failures? What if we’re making more of a post-apocalyptic game, or a survival game, and we want our players to barely succeed, to have to fight and struggle for every minor victory. A simple way to do this is to change one thing: instead of rolling 1d20 for skill checks, roll 2d10, or two ten-sided dice.
Is that the same? Nope! When you have multiple dice and add them together, a bell curve tends to form around the middle value of the possible sums. Despite the fact that 2d10 still has basically the same range as 1d20 (2-20 vs. 1-20), there’s only one way to roll a 10 on 1d20 (rolling a 10), but there are tons of ways to roll a 10 on 2d10 (1 and 9, 2 and 8, 3 and 7, 4 and 6, 5 and 5, 6 and 4, and so on). Meanwhile, there remains only one way to roll a 20 (rolling two 10s). Thus, those middle results become more common. Set your average difficulty numbers right around the middle of that bell curve, and you’ll find players frequently barely succeeding.
(This post on Glimm’s Workshop details this point extremely nicely.)
Let’s talk about one of my games. In Asphyxia, I want to capture the feeling of a tactical operation slowly going badly as it goes on and complications arise. I want players to start a mission feeling like kings of the world, and have this world basically beat them down until they drag the shells of their former selves back home, clutching onto anything they still have. I could have used a simple d20 roll-higher system like D&D, but that doesn’t really capture that sense of increasing peril, does it? There had to be something more interesting.
In fact, there is, and as it turns out, I found a way to capture the mood I want in something as soulless as the dice mechanics. Here they are, in simplified form:
- When characters want to do something, they take 2d10s and roll them. If either comes up lower than their Target Number (set by their ranks in any relevant skills), they succeed.
- Assorted bad things in-game (wounds, damage to equipment, and stress, primarily) will add Disadvantage Dice, which are d6s, to these rolls.
- If, in a dice roll, any Disadvantage Dice come up as the lowest result of a roll, no matter how good the d10s came up, the check is automatically failed.
I purposefully designed this system with a few nuances in mind. Players are going to receive constant visual reminders of exactly how bad things are going, as they add more and more of these bad dice to their rolls as the session goes on. Disadvantage Dice are powerful, as they average lower as d6s than the d10s the players normally roll. However, d10s have a 0 as the lowest result, while d6s only have a 1, meaning no matter how bad things are going, players always have at least a slight chance to squeeze out a victory.
This is what I mean when I say that core dice mechanics are the most important part of a tabletop role-playing game. By designing this central dice mechanic in a way that emphasizes my core theme, I ensure this theme will seep in to every part of the game which involves this core dice mechanic, which will be basically every part of the game.
If you take the leap into the world of tabletop RPG design (I highly recommend it, it’s one of the most interesting sandboxes as far as the design space goes), think about your dice mechanics. Read some RPGs with “weird” dice mechanics. Think about different configurations of dice that you could roll, different ways to interpret their result, and think about how those configurations and interpretations could be designed to suit your game.