4 AP per turn
Can be increase or lowered per turn using magic or being under effect
Standing your two feet's in a oil flask will result in a -1 AP for that turn
Using Haste magic in Pyrotechnic tree result in +1 AP for 3 turn if I'm not mistaking
Elves have an ability that gives +1 AP (with +damage -constitution) for a turn
Assassin have a skill that will give +2 AP for the turn and -1AP next turn
There are other effect than that but yes an Elf Assassin with Haste backstabbing someone, can be deadly
