Caltraps behavior

If you smash something fragile, shards may appear, made from the same material as the original item.

Ninja can throw sharp shards or spikes under their enemies' feet.

A shard or spike underfoot may lodge in the flesh and keep gnawing at it. Tear the stuck splinter out and you reopen the wound for a fresh jolt of pain -- and a blinded hand cannot pick it free cleanly, so it hurts all the more.