- A lava flow erupts from floor. It moves outward 1d4x5 feet per round, and cools after 1d4 rounds;
- A wave of Necrotic Energy bursts down from ceiling. Constitution saving throw for 1/2 damage. No healing this round for anyone;
- Lightning bolts from left wall in a line 10-feet wide;
- Make items blink in and out of the ethereal plane;
- An electric field would shoot up from the floor making it look like one half of a tic tac toe board, to mess with line of sight;
- The squares would move prompting anyone standing on a moving square to make a dex save vs. lava damage;
- A mist or stream fills lair, and heavily obscure within 20ft;
- A white glass orb rotates in the air like large drift globe, it will shoot rays of radiant light down;
- An anti magic field encompasses the interior of the lair;
- Flash goes off, 1d10 determines direction you end up flying in;
- Sheild forms around boss from a spell of 5th level or lower, for 10 minute.
- Gravity reverses;
- Fire fills one quadrant for 1 round. Roll 1d4 for which section.
- Magical piercing spears fly out from the right wall, Dexterity saving throw to avoid.
- Acid Rain from roof for 1 round. Everyone in the open takes some damage at the start of their turn, and again at the end of their turn if still out in the open.
- Water or lava, fills the floor with 6 inches of water/lava. Dramatic effect, but may cause interactions with certain spells or lair actions.
- Cold air fills the arena, Constitution saving throw or half movement. Ice forms at end of round requiring a Dexterity saving throw to move more than 1/2 speed, failure by 5 or more results in falling prone for 1d4 rounds (or until some effect warms it up).
- A cloud of poisonous gas appears moving in a random direction (cloudkill). The cloud doesn't dissipate on its own.
- Lasers of radiant energy target 6 of the players (level 20 sacred flame)
- A wall of whirling blades begin moving around the arena in a circular pattern, forcing movement in a specific direction.
- A 20-foot radius Darkness spell appears centered on a random player.
© 2021 Margaret Livingstone
Comments