OK, so accuracy conveys a benefit/deficit to damage done. We could get away with that, but we'll want to keep random values to a minimum. A bit of randomness is OK, but damage that can vary by 100% is merely tedious.

Are we also going to have the accuracy diminish over range. Seems reasonable really.

Also depends on how far the opponent has moved in its last turn.

Right, summary of modifiers:

Range
Chips
Target square terrain
Enemy movement
Friendly movement
A small random element