How about this? Just a basic AP thing.
The heavier your armor, the less AP you generate per turn.
The heavier your weapon, the more AP it will cost to swing or throw.
-Strength affects the percentage of AP you lose per turn for armor, and how much more AP it will cost to swing a weapon.
The more complex your bow is, the more AP it will cost to shoot.
-Dexterity affects the percentage of AP it costs to shoot more complex bows (like compound bow, crossbow, etc)
-Perception is something else.
The more powerful/complex your spell is, the more AP it will cost to cast.
-Intelligence affects the percentage of AP it costs to cast more complex spells.
The heavier your armor, the more AP you will have to spend to move.
The type of terrain affects the amount of AP required to move.
-Speed affects the amount of AP it costs to move to places. A higher speed will allow you to spend less AP moving, as well as how fast you reload your weapon (if it is ranged, such as a bow, or throwing daggers)
Getting poisoned/frozen/burnt will increase the amount of AP it will cost to use any action.
Being drunk will increase the AP cost of any action.
Being knocked down will cost a certain amount of AP to pick yourself back up.
-Constitution lowers the amount of AP it costs to take actions under these circumstances by a percentage.
AP is static and/or increases as you level. AP Regeneration is static and/or increases as you level up.
Just a thought.
