Discussion on answer by kviiri: PC ate a necklace of fireballs bead. How dead should they be?

Would this really be killing the character on a whim? If a character swallows live explosives to see what will happen, having him explode seems like a quite reasonable consequence consistent with the (rather stupid) decision he made. Personally, I think that having it not explode immediately is preferable, mainly because "You now have unexploded ordinance in your stomach" is a much more interesting scenario than "Nothing happens" or "You die". But if it does kill him, that's a result of his choice, not the DM's whim.

@kviiri if "GM's choice" = "whim" then D&D is inherently whimsical. Well over 50% of all that happens in a campaign is at the discretion of the GM. (And just to preempt this counterargument: If the GM uses randomizer tables to generate content, runs published adventures, etc., then the decision to use those materials is still a GM choice.)

@kviiri I'm just not there with you the "not foreseeable" nature of the act.