1

Explodes prematurely.

2

Total dud. Doesn't explode, and never will.

3

Doesn't explode when expected. 1 in 2 chance of exploding the next time it's handled.

4

Explosion is only half as powerful as expected.

5

Explosion is delayed by 3d6 seconds or d3 combat rounds.

6

Explosion is larger than expected. Causes unintended collateral damage or chain reaction.