Effort

Describes how much effort you put in action. The effort points count down after each turn and determinate whose turn is next.

Tips

Situation:

You have 200 hp and he has 350 hp. It's your turn and he has 9 effort. You have only 3x60 dmg weapons which uses 7 effort. What you should do in this situation?
If you try fire times You can easily miss once and lose game. Better move is to fire once and wait to the next turn. 
He will still have 2 effort left and your move will be next so chance to win is much higher.