I have a little thing in Unity that spawns a hundred blocks in a tight space, with many of them overlapping. Then I let the physics do its thing and spread them out somewhat randomly. The problem is that sometimes I find one block completely inside of another, and for some reason Unity decides nothing is wrong and no collisions or anything happen. It’s just stuck in there.

The solution I found is to make the rigidbodies’ collision mode “ContinuousDynamic” before letting them loose. This makes it much less likely for the blocks to be completely inside one another.