Scion said:
I changed it to per day to make it integrate with the system better. Levels happen too randomly to really be able to think of it as an actual character perk and if someone actually spends resources on boosting them somehow then a good portion of their character becomes useless after awhile.. gah.
Actually, level increases can be predicted quite well, even if the time might vary strongly - if you use the standard XP system, that is. If the players take long to level, they probably have a lot of easy encounters and situations where they don't need there action points (and the action point fueled special powers).
But I admit, I am not a fan of using levels to gain action points, either.
A thing to consider is not only the question when action points reset or accumulate at the chosen interval.
Accumulating can make waiting for special abilities fueled by Action Points more rewarding (see a Fast Hero/Gunslinger in D20 Modern, that is eagerly awaiting his Bull's Eye ability), but it can also unbalance the characters (while in the "collect"-phase, the character will seem weaker as the rest, but in the "burn"-phase, he gains power).
Resetting forces people to use their action points, but if they are not required between the reset phases, it feels like wasting important powers.
If you want to take Action Points to extreme, the Token mechanics of Iron Heroes are great, but they would need a lot of work to incorporate into the regular class system, I think.
The advantage of Iron Heroes is that you can decice yourself if you want to have action points (Tokens) and spend time (resources) to it. You can do without your Tokens, if you like, or you gather Tokens and then use them for your "special moves".