Upon triggering, variously colored beams of powerful magical energy flash on from hidden locations in the walls and ceiling. Each beam has a different effect. Characters may attempt to evade (AC, Dex, or Saving throw, GM's choice). Anyone hit rolls 1d6:
1 -- Petrification Ray Turned to stone.
2 -- Freeze Ray Take 6d4 from cold damage.
3 -- Madness Ray Permanently feeble-minded. (Requires magical healing, if available.)
4 -- Heat Ray Take 6d6 from burning damage.
5 -- Mute Permanently incapable of using their larynx. (Requires magical Healing, if available.)
6 -- Heat Ray again Take 6d6 from burning damage, but the beam also acts like a laser. Character must also roll 1d100 to see which extremity has been severed: 01-20%, left leg; 21-40%, right leg; 41-60%, left arm; 61-80% right arm; 81-00% head (death).
Gold lights Joel Muniz Unsplash License modified with Inkscape by David