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Twin

Legacy Content

Source Core Rulebook pg. 283 4.0
These weapons are used as a pair, complementing each other. When you attack with a twin weapon, you add a circumstance bonus to the damage roll equal to the weapon’s number of damage dice if you have previously attacked with a different weapon of the same type this turn. The weapons must be of the same type to benefit from this trait, but they don’t need to have the same runes.