Vae School (4e Feat)
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You have learned House Vae's fighting style.
Benefit: Once per round, when you deal damage to a foe that you have combat advantage against with a spiked chain or Scourge, you can attempt to trip the foe that foe as a free action. Make an attack (Strength or Dexterity Vs. Reflex defense); if you hit, your opponent is knocked prone.