breaking walls

is there a way to make it were you can break through walls with a sledgehammer?

Here’s a similar thread I replied to a while ago:
This example involves crates but the technique should be equally applicable to walls. You would probably have to break your wall up into shorter sections, then have a bunch of wall fragments animated to break apart all parented to an empty on another layer - like the exploding crate in the example. To trigger it, instead of a click you could use a collision sensor that would detect the sledgehammer object hitting the wall section. If you need any help in applying the technique to a wall post here. I may be able to make a demo blend if you need it.