Over the past few years I’ve looked at a lot of the probabilistic and statistical aspects of specific game designs, from the Japanese game Double Cross 3 to Pathfinder, including comparing different systems and providing some general notes on dice pools. I’ve also played various amounts of World of Darkness, Iron Kingdoms, D&D, Warhammer 2 and 3, and some Japanese systems, that all have quite diverse systems. Given this experience and the analytical background, it seems reasonable to start drawing it all together to ponder what make for some good basic principles of RPG system design. I don’t mean here the ineffable substance of a good RPG, rather I mean the kind of basic mechanical details that can make or break a system for long term play, regardless of its world-building, background and design. For example, I think Shadowrun might be broken in its basic form, to the extent that people who try playing it for any length of time get exasperated, and this might explain why every gaming company that handles Shadowrun seems to go bust.
So, here is a brief list of what I think might be some important principles to use in the development of games. Of course they’re all just my opinion, which comes with the usual disclaimers. Have at ’em in comments if you think any are egregiously bad!
- Dice pools are fun: everyone likes rolling handfuls of dice, and the weighty feeling of a big hand of dice before a big attack really makes you feel viscerally there, in comparison to a single d20
- Big or complex dice pools suck: Big dice pools can really slow down the construction and counting parts of rolling a skill check, but on top of this they are basically constructing a binomial distribution, and with more than a couple of trials (dice) in a binomial distribution, it’s extremely hard to get very low numbers of successes. So large and complex dice pools need to be limited, or reserved for super-special attacks
- Attacks should use a single roll: Having opposed skill checks in combat means doubling the number of rolls, and really slows things down. Having cast around through a lot of different systems, I have to say that the saving throw mechanism of D&D is really effective, because it reduces the attack to one roll and it makes the PC the agent of their own demise or survival when someone attacks them. On the other hand, rolling to hit and then rolling to damage seems terribly inefficient
- Where possible, the PC should be the agent of the check: that is, if there is a choice in the rules where the GM could roll to affect the PC, or the PC could roll to avoid being affected by the GM, the latter choice is better. See my note above on saving throws.
- Efficiency of resolution is important: the less rolls, counts and general faffs, the better.
- Probability distributions should be intuitively understandable: or at least, explainable in the rules – and estimates of the effect of changes to the dice system (bonuses, extra dice, etc.) should be explained so GMs can understand how to handle challenges
- Skill should affect defense: so many games (D&D and World of Darkness as immediate examples) don’t incorporate the PC’s skills into defense at all, or much. In both games, armour and attributes are the entire determinant of your defense. This is just silly. Attributes alone should not determine how well you survive.
- Attributes should never be double-counted: In Warhammer 3, Toughness determines your hit points and acts as soak in combat; in D&D strength determines your chance to hit and is then added again to your damage. In both cases this means that your attribute is being given twice the weight in a crucial challenge. This should be avoided.
- Fatigue and resource-management add risk and fun: Fighting and running and being blown up are exhausting, and so is casting spells; a mechanism for incorporating this into how your PCs decide what to do next is important. Most games have this (even D&D’s spells-per-day mechanism is basically a fatigue mechanism, if a somewhat blunt one), and I would argue that where possible adding elements of randomness to this mechanism really makes the player’s task interesting. But …
- Resource-management should not be time-consuming: this is a big problem of Warhammer 3, which combined fatigue management with cool-downs and power points. Too much!
- The PCs should have a game-breaker: we’re heroes after all. Edge, Fate, Feat points, Fortune … many games have this property, and it’s really useful both as a circuit-breaker for times when the GM completely miscalculates adversaries, and as ways for players to escape from disastrous scenarios, and to add heroism to the game
- Skills should be broad, simple and accessible: The path of Maximum Skill Diversity laid out in Pathfinder is not a good path. The simplification and generalization of skills laid out in Warhammer 3 is the way to go.
- Wizards should have utility magic: the 13th Age/D&D 4th Edition idea of reducing magic to just another kind of weapon is really a fun-killer. The AD&D list of millions of useless spells that you one day find yourself really needing is a much more fun and enjoyable way of being a wizard. It’s telling that D&D 5th Edition has resurrected this.
- Character classes and levels are fun: I don’t know why, they just are. Anyone who claims they didn’t like the beautifully drawn and elaborate career section of Warhammer 2 is lying. Sure, diversity should be possible within careers but there should be distinction between careers and clarity in their separate roles (something that, for example, doesn’t seem to actually be a strong point of Iron Kingdoms despite its huge range of careers). At higher levels characters should really rock in the main roles of their class
- Bards suck: they just do. Social skills should be important in games, but elevating them to a central class trait really should be reserved for very specialized game settings. Bards suck in Rolemaster, they suck in D&D, they suck in 13th Age and they suck in Iron Kingdoms. Don’t play a bard.
- Magic should be powerful: John Micksen, my current World of Darkness Mage, is awesome, but mainly because he is cleverly combining 4 ranks in life magic and 3 ranks in fate magic with some serious physical prowess and a +5 magic sword (Excalibur, in fact!) to get his 21 dice of awesome. Most of the spells in the Mage book suck, and if you made the mistake of playing a mage who specializes in Prime and Spirit… well, basically you’re doomed, and everyone is going to think you’re a loser. Mages should be powerful and their powers – which in every system seem to come with risk for no apparent justifiable reason – should be something that others are afraid of. You’ll never meet a World of Darkness group who yell “get the mage first!” What’s the point of that?
- Death spirals are important: PCs should be aware that the longer they are in a battle, the more risky it gets for them. They should be afraid of every wound, and should be willing to consider withdrawal from combat rather than continuing, before the TPK. Death spirals are an excellent way to achieve this combination of caution and ultra-violence. Getting hit hurts, and players should be subjected to a mechanism that reminds them of that.
I don’t know if any game can live up to all these principles, though it’s possible a simplified version of Shadowrun might cut it, and some aspects of the simplified Warhammer 3 I used recently came close (though ultimately that system remains irretrievably broken). Is there any system that meets all of these principles?