I'm running theboy through a solo D&D 3.5 game, he has an NPC ally, but because he's new to it and because he was a dwarven wizard and we had a fig of one with a flaming club I started him off with a club that could cast scorching ray three times a day. This session he insta-killed the large-sized spider that he, the NPC and three goblin allies were set up to take out and his readied action with the ray got a nat 20 with a confirmed crit which resulted in -10 hit points or more and death. He was the first to act. Adios spider.On the way out four stirges came flying in and he nat 20 critted the first for so much damage I decided it had fed on whale, was rich with blubber, and caused a cascading series of stirge explosions as each next in the line blew.Smoked stirges crisped and left behind as the dungeon was exited. The goblins, with dreams of civilisation, were forced to live in the dungeon needing a hundred gold each to pay a bond to enter the city. They had money left over from entry to get apprenticeships to a legal firm specialising in maritime law (and have exp to get a level in Expert), but in time they will strike out and setup offices in their own names of "Rock, Stone and Pebble".This is now the third set of critter/s he has taken out with scorching nat 20s, the first a dire badger.So when he did it to the giant arachnid I said "I can't believe you dire-badgered my spider".Only in D&D.