Have a good chunk of the floor made of Bronze, Gold, or something with ya, a low melting point. Then the dragon hits it with his breath, and it melts. People standing on top of it sink down into it. Treat it as the Mud from the Transmute Rock to Mud, as well as doing 8d6 fire damage per round, and some damage the following rounds they get out, unless they scrape it off. Then when it hardens, treat as Transmute Mud to Rock.
If it's in a cave (I don't advise most of it to be; allow the dragon to fly), have parts of the ceiling carved outward, or wittled down. Think of a big slab of the ceiling hanging by very little, because the dragon has gnawed and clawed a deep groove behind the slab. It flies up, *Yanks*, and this big, enormous chunk of the ceiling falls.
Uneven floor. PCs can't charge, must make balance checks to move at full speed, and get a penalty to their dex, maybe. THe dragon doesn't need even floor; imagine it if it's broken and jutting everywhere.
Perhaps it has a smaller dragon mate. Not a red, though (The party would Expect a red). Imagine their horror when they are attacked from BEHIND by an old Black dragon female. They don't have acid protection. This allows you to do some other stuff, like have the Black dragon drop Gelatinous Cubes on the PCs, or some other ooze; Black dragons are immune to both acid and paralysis.
If it's in a cave (I don't advise most of it to be; allow the dragon to fly), have parts of the ceiling carved outward, or wittled down. Think of a big slab of the ceiling hanging by very little, because the dragon has gnawed and clawed a deep groove behind the slab. It flies up, *Yanks*, and this big, enormous chunk of the ceiling falls.
Uneven floor. PCs can't charge, must make balance checks to move at full speed, and get a penalty to their dex, maybe. THe dragon doesn't need even floor; imagine it if it's broken and jutting everywhere.
Perhaps it has a smaller dragon mate. Not a red, though (The party would Expect a red). Imagine their horror when they are attacked from BEHIND by an old Black dragon female. They don't have acid protection. This allows you to do some other stuff, like have the Black dragon drop Gelatinous Cubes on the PCs, or some other ooze; Black dragons are immune to both acid and paralysis.