Knockback

Knockback is a basic mechanic in Terraria, whereby players and enemies are repelled in the opposite direction of an attack. Most weapons and environment objects that cause damage also cause knockback, to varying degrees. Some enemies are immune to knockback, particularly Bosses and other enemies that travel through blocks, like Worms and Man Eater. The Cobalt Shield grants the player knockback immunity.

Knockback can be used in a manner similar to the Grappling Hook to accelerate to Hermes Boots speed instantly.

The most player-induced knockback currently can be inflicted using the Thorns Potion, which has a knockback value of 10. This is followed immediately by the Enchanted Boomerang, Flamarang, Thorn Chakram, Light Disc, Hellfire Arrow, Grenade, and Breaker Blade, which all have a knockback value of 8. Also various modifiers and the Titan Glove can increase the knockback.

Knockback Values
 * 0: No knockback
 * 1: Extremely weak knockback
 * 2: Very weak knockback
 * 3: Weak knockback (?)
 * 4: Average knockback (?)
 * 5: Strong knockback (?)
 * 6: Very strong knockback (?)
 * 7: Extremely strong knockback (?)
 * 8: Extreme knockback
 * 9+: Insane knockback

Immune NPCs
Other:
 * All Bosses except Brain of Cthulhu in it's second phase.
 * All Plants
 * All Worms
 * Antlion
 * Blazing Wheel
 * Dungeon Guardian
 * Lihzahrd
 * Paladin
 * Pirate Captain
 * Spike Ball
 * Headless Horseman

History

 * 1.0.6: The Cursed Skull is no longer immune to knockback.