You invoke the fading power of the world as you strike.

Encounter   ✦     Primal, Thunder, Weapon
Standard Action      Melee weapon

Target: One creature

Attack: Primary ability vs. AC

Hit: 1[W] + ability modifier thunder damage.
Level 11: 2[W] + ability modifier thunder damage.
Level 21: 3[W] + ability modifier thunder damage.

Effect: You mark the target until the end of your next turn.
Until the mark ends, if the target makes an attack that does not include you, it takes 5 thunder damage.
Level 11: 10 thunder damage.
Level 21: 15 thunder damage.

Published in Dark Sun Campaign Setting, page(s) 58.