I dole out level-ups somewhat more sparingly than most, operating under more of an actual-play cadence of one level-up per 'chapter'. The adventure structure that has come out of this mini-boss midway through the adventure, mid-boss guarding the adventure goal, and then adventure boss after level-up.
This time, they beat the dungeon boss, gathered the treasure (a relic crossed with a spell heart, giving them access to higher ranked spells than they 'should' have), and now they're facing... basically all of the enemies (and potential allies) in the dungeon that they bypassed.
This isn't an easy fight. This is a custom-tooled run of the Forge of Fury. They wiped out the Orcs on the main floor, by bypassed almost all of the Troglodytes, and almost all of the undead.
They befriended the Duergars, at least.
I've given everyone control over the Duergars (9 in total), so everyone is playing 4 characters this fight. They got through a couple of rounds of combat last session just fine, and everyone was into it.
Then last night, one of the players -- my partner -- managed to roll a 1 on every. Single. Damage roll. Like, her dice just decided they could not stand the sight of her anymore. It got to the point where I started to let her just re-roll her first roll if it was a 1, and about half the time it still came up a 1.
So, near the end of the session, as this well established itself as a giant cosmic joke, I pitched cascading damage dice to everyone, triggering off of a 1. They all agreed -- though one of the kids was sharp enough to ask if enemies would get the same benefit (of course they would) -- and we finished off the session giving it a try.
My partner rolled a lot of additional dice in the last halaf-hour of play. I let d4s trigger a second d4, but didn't let the secondary die explode. The mood at the table lightened considerably. The damage output increased negligibly, as 1s begat more 1s.
I've never played with exploding or cascading dice before. I don't have the bredth of system experience to have come across it organically. I was pleasantly surprised with how it added tension to damage rolls, and everyone else really loved how it softened the disappointment of rolling strong on their d20 only to find that they actually struck their enemy with a wet noodle.
I'm looking forward to next week, where I'll get to see how this plays out over a longer period of time. I think the kids are going to get a lot out of it, if they ever start rolling 1s.
Quick, someone recommend traveler's insurance!