[thejeff]

Trample definitely doesn't use up all the action points. I'm not sure of the actual mechanics, but it looks like a trample only counts as a normal move. The move happens, and displaces the targets whether or not the actual attack succeeds. Then they can try to trample again.

I've often seen high def units get moved all around the field before finally being squished, so I'd assume they just get enough chances to get the 5% hit.