I want to discuss the merits and downfalls of
dissociated mechanics.
For those not initiated enough to follow the link, I have spoilered the relevant text below.
Dissociated mechanics are those that have no in-game explanation.
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Relevant portions:
[spoiler]
At first glance, this [ability] looks pretty innocuous: The rogue, through martial prowess, can force others to move where he wants them to move. Imagine Robin Hood shooting an arrow and causing someone to jump backwards; or a furious swashbuckling duel with a clever swordsman shifting the ground on which they fight. It's right there in the fluff text description: Through a series of feints and lures, you maneuver your foe right where you want him.
The problem is that this is a Daily power -- which means it can only be used once per day by the rogue.
Huh? Why is Robin Hood losing his skill with the bow after using his skill with the bow? Since when did a swashbuckler have a limited number of feints that they can perform in a day?
There's a fundamental disconnect between what the mechanics are supposed to be modeling (the rogue's skill with a blade or a bow) and what the mechanics are actually doing.
Of course the argument can be made that such explanations can be trivially made up [for the war devil's besiege foe ability]: A ruby beam of light shoots out of the war devil's head and strikes their target, afflicting them with a black blight. The war devil shouts horrific commands in demonic tongues to his allies, unnaturally spurring them into a frenzied bloodlust. The war devil utters a primeval curse.
These all sound pretty awesome, so what's the problem? The problem is that every single one of these is a house rule. If it's a ruby beam of light, can it be blocked by a pane of glass or a transparent wall of force? If it's a shouted command, shouldn't it be prevented by a silence spell? If it's a curse, can it be affected by a remove curse spell?
And even if you manage to craft an explanation which doesn't run afoul of mechanical questions like these, there are still logical questions to be answered in the game world. For example, is it an ability that the war devil can use without the target becoming aware of them? If the target does become aware of them, can they pinpoint the war devil's location based on its use of the ability? Do the war devil's allies need to be aware of the war devil in order to gain the bonus?
If the mechanic wasn't fundamentally dissociated -- if there was an explanation of what the mechanic was actually modeling in the game world -- the answers to these questions would be immediately apparent. And if you're slapping on fluff text in order to answer these questions, the answers will be different depending on the fluff text you apply -- and that makes the fluff text a house rule.
Of course, you can sidestep all these issues with house rules if you just embrace the design ethos of 4th Edition: There is no explanation for the besieged foe ability. It is a mechanical manipulation with no corresponding reality in the game world whatsoever.
At that point, however, you're no longer playing a roleplaying game. When the characters' relationship to the game world is stripped away, they are no longer roles to be played. They have become nothing more than mechanical artifacts that are manipulated with other mechanical artifacts.
You might have a very good improv session that is vaguely based on the dissociated mechanics that you're using, but there has been a fundamental disconnect between the game and the world -- and when that happens, it stop being a roleplaying game. You could just as easily be playing a game of Chess while improvising a vaguely related story about a royal coup starring your character named Rook.
[/spoiler]
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I personally strive for as few dissociated mechanics as possible. I see dissociated mechanics a lot in fighter fixes, the most recent being "You can't approach the fighter at full speed." There is no possible circumvention for this ability except being 3 CR higher than the fighter, no matter how stoic your character is designed to be.
I like it when I can roleplay every precious second of combat if I want. I think even abilities like plan-jumping for fighters can be explained with slicing a hole in the fabric of reality. just need it to be explained!
What are your opinions of dissociated mechanics?
What sort of dissociated mechanics have you seen in any game?
I definitely don't want this discussion to turn into a flame war about 4E. Using examples from 4E is acceptable, as long as it is to prove a point.