[Mutant Future] Cover!

Combat got tactical, combatants are behind different natural covers. Walls, rocks, behind the windows, bushes etc. How does it affect?

In my opinion it is too much trouble to add or decrease numbers from D20 to-hit roll so it affects AC. It's easier that way.

• Partial Cover 25%: AC -2
• Half Cover 50%: AC -4
• Full Cover 75%+: AC -6

Partial cover might be behind a rock waist down.

Half cover might be behind a window shooting.

Full cover might be laying low behind a bush.