From Guild Wars 2 Wiki
Weapon swap is the mechanic of switching between the two equipped weapon sets (default key: ). This ability is unlocked when your character reaches level 7 for all professions except Engineers or elementalists, who use a similar mechanic.
- During combat, swapping has a cooldown of 10 seconds, but you can swap repeatedly out of combat.
- There are several traits and sigils effects that trigger on swapping.
- If you choose to leave an off-hand slot empty, the game will automatically use the off-hand from the first set when you switch to the second.
- Engineers can trigger on-swap effects by changing kits; elementalists do so by switching between attunements.
- Switching to an environmental weapon will also trigger on-swap effects.
- Versatile Rage (gain 5 strikes of adrenaline)
- Fast Hands (cooldown reduced by 5 seconds)
- Versatile Power (gain might for 10 seconds)
- Tail Wind (gain swiftness)
- Furious Grip (gain fury)
- Quick Pockets (gain 3 initiative)
- Superior Rune of the Warrior (rank 6 – weapon-swap cooldown reduced by 1 second)
- Sigil of Battle (gain [2, 3] stacks of might for 20 seconds)
- Superior Sigil of Doom (next attack poisons)
- Superior Sigil of Energy (gain 50% endurance)
- Superior Sigil of Geomancy (bleeds nearby foes for 7 seconds)
- Superior Sigil of Hydromancy (freeze nearby foes for 3 seconds)
- Superior Sigil of Intelligence (next attack has a 100% critical hit chance)
- Superior Sigil of Leeching (next attack steals health)
- Rearranging or equipping a different set of weapons is not the same as swapping. This can be done outside of combat, but never during combat. It never triggers on-swap effects.