Guild Wars 2

Is the damage dealt by the Retaliation boon based off of the player’s power that generated the boon, or based on the damage dealt by an enemy hit? If its based on the player’s power then the tool tip needs a complete rewording. It does actually reflect damage (reduce damage tanken) back nor is it based on the enemy damage dealt.

Retaliation does not reduce damage taken by the affected player, but damages anyone who hits them (even if the hit doesn’t actually inflict damage; for example, if it is blocked).

Damage dealt depends on the level and power of the retaliation’s source. Retaliation deals 267 damage per hit at level 80 with the base power of 916, and +1 damage for every 13.4 power above that. It is not reduced by the target’s armor.

http://wiki.guildwars2.com/wiki/Retaliation