Here is another installment of exTRAPaganza, our Thursday over-the-top trap series.
This room is almost exclusively made from windows. Several of them show cracks.
When any area of effect spell that causes damage is cast, or if any missile weapon misses a target, the windows all shatter.
Those in the room must make a hard Dexterity saving throw, or take 1d6 piercing and slashing damage for each window that is shattered, which is up to the DM’s discretion.