An ally with full plate and tower shield is in the area of a grease spell. It is impossible for him to get out of the grease without help (Acrobatics -13 against DC 10). I am standing near him but not in a greased square.
First question: What will happen if i use a combat maneuver (bullrush, reposition, grapple) to move him out of the greased area ?
Second question: Can i use the aid other action to help him with the acrobatics check? (not useful in this case but useful in general)
Third question: I cast fly on him and he fly away. He is moving 5ft. and leaves a greased square. Acrobatics check ? (I know that magical fly and the prone condition are another problem)
Thanks :)
1. You would affect them per the rules for the maneuver you performed, provided you succeed at your check. There is some argument as to whether an ally can (a) choose to allow your maneuver to auto-succeed; (b) choose to forgo their Dex bonus against your maneuver while retaining it against other attacks; or (c) choose to forgo their Dex bonus against your maneuver, thereby losing it against all attacks until their turn. I don't really have any help with that; RAW doesn't cover voluntarily allowing an ally to attack you with anything other than a (harmless) spell.
2. Yes. It could even help in your situation (albeit marginally) if multiple party members are able to Aid Another.
3. The spell only mentions that a creature has trouble walking through the area. Since flight does not require a running start or anything, it follows that flying out of the square would not be an issue.