1-2

Nightmare of a shrinking room. The room begins to shrink, and after five rounds, the room is so small that it crushes everyone inside. Each creature takes 1d6 bludgeoning damage per round for every other creature in the room. For example: if there are five creature in the room, then each creature takes 4d6 damage per round.

3-4

Nightmare of falling. The room and chair vanish, and everyone inside the room begins to fall. After 10 rounds they hit the room's floor for 20d6 bludgeoning damage, and the nightmare ends.

5-6

Nightmare of being naked. At the end of every round, a non-magical item vanishes from each hero. At the end of 10 rounds, all remaining non-magical items vanish forever. If the nightmare ends early, then all of the vanished items return.

7-8

Nightmare of teeth falling out. At the end of every round, a tooth falls from the mouth of the dreamer. Each tooth instantly transforms into a monster that attacks and tries to eat the party. The tooth-monsters appear in this order: 1. Skeleton, 2. Griffon, 3. Minotaur, 4. Gorgon, 5. Mezzoloth, 6. Salamander, 7. Cyclops, 8. Chimera, 9. Grick Alpha, 10. Nycaloth

9-10

Nightmare of drowning. Blood gushes from the mouth of the dreamer and fills the room in two rounds. Use the drowning rules. Water breathing does not work, because the liquid is blood.