First, the context: The PCs have blitzed through my 4e conversion of Dragon Mountain and it's been crazy fun. I think they've triggered close to every damn kobold trap known to man. ;) They're heading into the climactic dragon fight tomorrow night (it's Infyrana, a big bad red dragon mage). One of the things I've worked into the dragon fight is a portal which she can move around (and at a certain point use a limited spell to teleport PCs into, they'll get a save as per the rules of course); this portal leads to the "Kobold Proving Grounds" which are where kobolds learn to fight and think like, well, kobolds
So this trap is a prison of sorts, with the PC removed from the dragon fight and facing a gauntlet of traps which tests that player's knowledge of kobold trapping techniques that they've run up against throughout Dragon Mountain. It has the potential of dealing 108 damage (average) to a PC who makes poor decisions, but at the same time the PC's player (mostly) has the option to not advance and stay stuck until they can puzzle it out or another player helps them. And it does all this without ever rolling an attack roll...
Broken? Awesome? What do you think? And how on earth do you assign a level to something like this?
Kobold Proving Grounds
Level 13 Elite Obstacle
Puzzle: Once trapped in the kobold proving grounds, the PCs must deduce a way out. Only PCs in the proving grounds together can help each other. While in the proving grounds, medium-sized PCs must squeeze (-5 attack, half speed, and grant combat advantage).
Targets: PCs ending their turn in the proving grounds.
Effect: Ask each PC these questions, in any order. A PC can choose to fall back when there’s an (*), but then they do not reach a possible exit that round.
1.* “You hear scything blades coming. What do you do?”
‘Duck’ or ‘drop prone’ avoids the trap. Otherwise the PC is impaled for 3d8+10 damage.
2. “A rolling boulder is coming down the hall behind you, and a kobold goes running down the hall ahead of you. How do you proceed?”
‘Skirting the edge’ or ‘mindful for pits’ avoids the trap. Otherwise the PC falls into a pit for 4d10 damage.
3.* “You notice bits of floating metal in the hallway ahead. In an alcove before the hallway are five potions, labeled as resistance to acid, cold, fire, lightning, and poison. What do you do?”
‘Acid’ bypasses the gelatinous cube for -1 surge. Otherwise, the PC takes 20 acid damage. Other potions do nothing but cost -1 surge. Mixing at DM discretion.
4. “A kobold ahead of you is crushed by a stone block. From either side of the hall, swarms of insects pour. Soon you’ll be dinner. How do you proceed?”
‘Trigger the deadfall’ avoids swarms, since the deadfall is hollow. Otherwise, the PC takes 4d8+5 damage.
5.* “This foul-smelling hall seems to swallow magical light and you hear a big monster within feasting on kobolds. What do you do?”
‘Throw a torch’ ignites the foul gas and provides a distraction. Other techniques might work. Otherwise the PC takes 20 poison damage.