Hi all! I have an encounter I think would be really fun to run but i am having difficulty fleshing out the specifics of it. Basically the idea I have is to have a large arena area with some stone structures for multiple levels and stuff that the party is trapped in. Their goal is to catch a small flying eyeball that is whipping and dodging around the arena. To complicate things, they are being hunted by 2-3 Otyughs at the same time (not fully decided on this monster, just needs to be something dangerous and distracting). I think this will kinda play out like a chase, but all within the same arena.
I am leaning towards using the official rules for a chase where a dash can give you a point of exhaustion since I think this will play out more like combat than an actual chase. I plan to give the eyeball a pretty high speed, maybe like 50 or so feet per turn and a dodge reaction. The rules of the game (the players are forced to compete here) will be that they may not attack the eye or they will be executed and it will be immune to magic effects like hold person or something that will just make it way too easy. I plan to make a really fun environment for this combat, complete with stairs and slides and ziplines to give players ways to zip around the arena quickly of they plan well.
Most of all I want this encounter to be fun so can anyone think of any way this might not turn out well? any ways you can think to break it? does it sound way too easy or way too hard? Any feedback and advice would be appreciated, thank you!