Running Colossal Cave as a setting recently reminded me that I once got a delightful three sessions of play out of the following notes. These were for a dungeon underneath a seaside city, with three traps from James Introcaso’s 20 New Traps and assembling the dungeon on the fly using tiles from The Sorcerer’s Cave (get your own set of tiles for this out-of-print game from here). I made sure that every monster was foreshadowed, using Monty Hall Prep, to give players agency over their decisions. This led to some interesting and memorable debates as players interpreted or misinterpreted clues and weighed their relative peril. Foreshadowing of rooms -> Monster Near submerged corridor Tiger sharks eat the dead sea monster you had slain Sailor uniforms, gear, rope, and other things sailors might have carried -> grick Set 1 Bats [if room not selected, hear bats take flight] -> stirge, will suck blood and retreat You hear the pitter patter of many tiny feet, Skeletons recently decorpsified -> carrion crawler Empty chamber with Tapestry [Withering Tapestry trap] Set 2 Immaculately clean passageway -> ooze Mushrooms and fungi -> myconid Empty chamber [Acidic Fall trap] Set 3 Beholder -> gas spore Gemstones (10 gp – Obsidian (opaque black), Hematite (opaque gray-black), Blue quartz (transparent)), bow, arrows no arrowheads, wood -> rust monster Treasure chest -> mimic Set 4 Stalactites and stalagmites -> piercer Mushrooms and fungi -> shrieker / violet Fungi -> shrieker summons another creature -> Grell 5 foot-wide, 8-foot-high tunnel in its wake -> umber hulk Set 5 Pool of water -> water weird Rock fall -> xorn Altar Room Blocked with a door with a sun and a moon on it: the moon has to be moved to eclipse the sun. Defaced statue of Mystra An altar with dried blood, lit by the sun Long chimney-like opening that lights altar [can be flown out of next to a smokestack from the Purple Portals] [Eclipses were considered holy, being accompanied by feasts, fervent prayers, and bloody sacrifices] [Zealous Altar trap]