Roleplaying games can be divided into two pieces: the fiction of the game (the story that everyone at the table is telling) and the mechanics of the game (the bit where you roll dice and find out what happens). The relationship between the two can be quite interesting when you dig into it, and can also explain the reaction of some people when faced with games which play with the relationship in unfamiliar ways – if you’re not used to thinking of the game as two separate threads it can be jarring to play a game which has that as its baseline assumption. (See also every blog post about ‘immersion’ and ‘dissociative mechanics’ ever.)
In D&D 3.x and other ‘trad’ roleplaying games most* mechanical elements are linked to a specific element of the fiction. The mechanics generate the fiction – when you make a trip attack, for example, your character is actually trying to knock down their opponent – but the fiction also generates mechanics to go with it. Creatures with extra legs have a mechanical advantage when defending against being tripped, and creatures with no legs (oozes) cannot be tripped at all. When the fiction seems like it should provide an effect but doesn’t – like enlarge person failing to provide an increase in movement speed – people find it incongruous.
You can also make the case that this is part of why games like this tend to get so rules-heavy: when you introduce new fictional elements, every element has to have a rule that goes with it and that rule has to interact with the rest of the system – if the system breaks, the fictional elements attached to that part of the system also break and the game suddenly becomes very surreal. You can see an example of this in core D&D with elementals: water elementals are made of water, yet have no special resistance to fire damage. This means that in the fiction of the game a spell like inferno can cause a water elemental to catch fire and burn to death. Which is a little odd.
*Hit points, of course, have never been linked to anything in the fiction except in the most handwavy way.
The fourth edition of D&D takes a different approach: the mechanics still generate the fiction, but the fiction does not drive anything mechanical. When 4e was first released a lot of people took umbrage at the warlord’s healing word power (I forget what it’s called) because they could see no way to tie the fiction – the warlord says something – to the mechanical healing effect. How does a warlord shouting close wounds generated by an axe to the head?
The answer according to 4e is ‘however it makes sense’. Perhaps that axe to the head was just stunning rather than wounding, or perhaps the loss of hit points was panic and not a direct physical hit – in either case, having a drill sergeant get on your case can get you back in the fight. You’re expected to tailor the fiction of the game to reflect what the mechanics tell you has happened, but the fiction has no reciprocal effect on the mechanics.
For another example, consider a 4e character’s ability to knock a gelatinous cube prone**. The fiction – that a gelly cube has no legs and no real facing – does not create a mechanical imperative that the cube cannot be knocked prone. Rather, when you bash the cube with a prone-making power you are expected to justify the mechanical effects (-2 on attacks, grants CA, can’t move) with some other fictional explanation, like “I’ve disrupted its membrane!” or something.
**I have vague memories of this being fixed in the Monster Vault – but you can still grab swarms, so the basic point remains.
FATE doesn’t veer too far from the trad games setup in that mechanical elements and fictional elements are specifically tied together, but it does offer the interesting ability to translate the fiction into mechanics just by writing it on your character sheet. Is the dungeon collapsing? Well, now there’s a Collapsing aspect on the scene. Get hit by a hammer and suffer a broken arm? Well, now you’ve got a Broken Arm that affects how you act.
This neatly avoids the problem of D&D 4e where the fiction seems to demand something that the mechanics don’t support*** – the fiction simply becomes the mechanics – and also the excessive rules pile-up of D&D 3.x by allowing the mechanics to interact with plain English phrases rather than requiring the translation of those phrases into mechanical code that can be plugged into the rules engine.
***Just why are mindless undead still susceptible to psychic damage?
Dungeon World also follows the trad games method of tying specific fiction actions to specific mechanical effects, but explicitly gives primacy to the fiction. It’s not quite an inversion of the 4e model, but it does create a situation where the results of mechanical dice rolls have to fall in line with the fictional paradigm already established – and if the fiction disallows a certain action, such as the frequent example of a dragon which is just too mighty to be fought with regular weapons, then the mechanical action cannot take place.
To be honest, I think this is what gives DW its ‘old-school feel’, since your Labyrinth Lords and your Swords and Wizardrys operate along very similar lines: declare fictional intent to stab goblin, roll to stab goblin, translate roll and damage back into fictional wounding of goblin; declare fictional attempt to climb wall, GM tells you wall is too slick, find another way around or break out some equipment; etc. etc.
Well, nothing really. But I have a post on D&D 4e skill challenges in the pipeline and I didn’t want to digress in the middle of that in order to a) explain what I mean when I say that the fiction in 4e is an epiphenomenon of the mechanics and b) defend that opinion when the post is about something else entirely.