Minecraft wiki entry for Hiding_chests, associated text: To prevent this from happening, this is where the redstone comes in. Put an observer observing the trapped chest, and connect it to a deadly trap, so if a smarter player tries to break the chest, they will not be happy with the results. The only disadvantage of this method is that if a player decides that they want to open the trapped chest despite the warning signs, they will be able to get all the loot in it without any consequences (this can be remedied by hiding the valuables somewhere else and turning the aforementioned chest into a mere decoy).