Generate a Tight Encounter Balanced for Your Party Level

You do not need a lecture on encounter design, you need a fight that fits your party and does not run long. This gives you enemy composition, one terrain twist, and one tactical wrinkle in a single tight brief, ready to run.

Generate one combat encounter for a tabletop RPG party at level {PARTY_LEVEL} with {PARTY_SIZE} players. Set it in [describe the location or situation, e.g. a collapsed mine, a noble's dinner party gone wrong]. Include: enemy composition with rough stat adjustments for the party size, one terrain feature that changes tactics, and one twist that stops it being a straight slugfest. Keep the output to a tight brief, no padding, assume I know the system.