Action Token System

OK, I am toying around with a strange sort of resolution mechanic and I am interested in the board's feedback on it. This is still firmly in the idea stage, I haven't tried implementing this in play. It completely eliminates the fortune aspect and focuses on character effort. I'm not sure if there are any games out there like this (Riddle of Steel's combat dice are similar, but not quite the same).

Each character has two pools determined by stats, a mental and a physical pool. These are pools of "tokens," for lack of a better term, which can be used to take actions in the game. The goal here is to simulate the allocation of physical/mental resources to any given situation.

Characters can take as many actions as they want in a resolution conflict (a fight, attempting to break something, hiding, etc.). Each action requires a minimum expenditure of one token. A minimum of one token must be spent to initiate an action (in other words, even if a straight stat/skill test would succeed, if the player doesn't allocate a token, the character doesn't even try). The player can choose to spend as many or few tokens as desired.

Success or failure is purely a threshold test--the character's basic ability (stats/skills) are compared numerically to a required target to overcome, and if the character exceeds the target, he succeeds. Each token applied adds to the stat/skill total when determining success. The rub is that the character cannot reallocate tokens in mid-action--if he is expending all physical tokens on some activity, and is suddenly attacked or the circumstances change, he has no further tokens to devote to the new factor. Sustained actions would occupy tokens for multiple conflicts.

Token allocation would also be subject to fatigue rules. If the player allocates a certain number of tokens to any effort, the character is fatigued and his token pool is diminished. The character can also be physically or mentally damaged, which would temporarily or permanently affect the token pools.

I can see many circumstances where both mental and physical faculties must be applied to succeed at a task. I haven't nailed down the interaction between the two pools, but I think that it would be easier to apply mental tokens to physical tasks than vice versa.