Slow is a debuff that halves the player's horizontal movement speed. It has a chance to be inflicted by direct contact from a Pixie, Wraith, Mummies or Rusty Armored Bones. The beams fired by Necromancers also have a chance to cause this debuff. Equipping the Fast Clock, The Plan, the Ankh Charm, or the Ankh Shield makes the player immune to the debuff.
|Pixie||15 / 30 seconds|
|Wraith||15 / 30 seconds|
|Mummy||15 / 30 seconds|
|Rusty Armored Bones||5 / 10 seconds|
|Necromancer||5-16 / 10-32 seconds|
|Skeletron Hand||0.5-1 seconds|
|Brain of Cthulhu||8.75-17.5 seconds|
|Deerclops||12 / 24 / 30 seconds|
|Feral Bite||2.1–3.5 seconds|
|Red Potion||1 / 2 / 3 / hours|
- If the player has any boots that increase movement speed, such as the Frostspark Boots, it will take much longer to accelerate, but the player can still move at the maximum speed allowed by the boots.
- If the player has nothing equipped that affects movement speed, they will move at the same speed even when the debuff is active.
- If the player is afflicted by the debuff and uses the sandstorm jump via Sandstorm in a Bottle, Sandstorm in a Balloon, or the Bundle of Balloons, they will spin much faster than normal during the ascent.
- Desktop 184.108.40.206: Now has a chance to be inflicted by Expert Mode Brain of Cthulhu and Creepers, as well as Skeletron's Hands.
- Desktop 1.2: Now inflicted by the Necromancer's beams, and Rusty Armored Bones as well.
- Desktop 1.1: Introduced.
- Console-Release: Introduced.
- Mobile-Release: Introduced.
- 3DS-Release: Introduced.