Any closable item (book, box, bottle, chest, coffer, coffin, door, drawer, and so forth) is affected by a fire trap spell, but the item so trapped cannot have a second spell such as hold portal or wizard lock placed upon it except as follows: if a fire trap/hold portal is attempted, only the spell first cast will work, and the other will be negated (both negated if cast simultaneously). If a fire trap is cast after a wizard lock, the former is negated, if both are cast simultaneously both are negated, and if a wizard lock is cast after placement of a fire trap there is a 50% chance that both spells will be negated. A knock spell will not affect a fire trap in any way — as soon as the offending party enters/touches, the trap will discharge. The caster can use the trapped object without discharging it. When the trap is discharged there will be an explosion of 5’ radius, and all creatures within this area must make saving throws versus magic. Damage is 1-4 hit points plus 1 hit point per level of the magic-user who cast the spell, or one-half the total amount for creatures successfully saving versus magic. The item trapped is NOT harmed by this explosion. There is only 50% of the normal chance to detect a fire trap, and failure to remove it when such action is attempted detonates it immediately. To place this spell, the caster must trace the outline of the closure with a bit of sulphur or saltpeter.