Check out my free Fire Up template in my OneHitGamer link in my profile. What i did was have say 3 blocks. 1 2 and 3. 3 being on top. 3 you set COLLISION to full object. Then 2, set collision slightly smaller. Then 1, even smaller. This way when a bullet hits 3, it doesn't hit the rest, but dies. Then 2 is on top. Bullet hits...but not 1....2 dies. etc. Just download my free template and move the blocks around and you will see. Also click on them in OBJECTS menu, then hit EDIT and look at how i setup their collisions. In a nutshell, the lesser numbered blocks are BEHIND the higher numbered blocks. But with small collision settings so they all don't die in 1 bullet hit.