It works everytime for me, you can only destroy cards that are "in play". So if for instance its the very first card you play in your hand then you'll have no options to destroy as there are no other cards in play yet. Works no differently to the Reachmen cards.
Personofsecrets wrote: »Are you playing against an NPC or human player?
You aren't getting the menu popup for selecting cards?
You aren't accidentally skipping the menu?
Are other sources of card destruction still working?
Is there a difference in how it works if you interact with the Tavern before using the Tombshell?
I believe this happened to me as well. I thought I had accidentally clicked confirm.
Otherwise, it works like the Reachmen cards, as mentioned prior.