Partially Invincible
To become partially invincible is easy.
When you do your shield, move to the side or crouch and you will roll out of the way (this can be repeated over and over again).
You can also do this in midair by repeatedly pressing the shield button.
This comes in handy when avoiding final smashes!!!
If you need more help, we've got more Super Smash Bros. Brawl cheats and also check out all of the answers for this game