Symbol of Weakness
This spell functions like symbol of death, except that every creature within 60 feet of a symbol of weakness instead suffers crippling weakness that deals 3d6 points of Strength damage.
Unlike symbol of death, symbol of weakness has no hit point limit; once triggered, a symbol of weakness simply remains active for 10 minutes per caster level.
Note: Magic traps such as symbol of weakness are hard to detect and disable. A rogue (only) can use the Search skill to find a symbol of weakness and Disable Device to thwart it. The DC in each case is 25 + spell level, or 32 for symbol of weakness.
Mercury and phosphorus, plus powdered diamond and opal with a total value of at least 5,000 gp.