Minecraft wiki entry for Sword, associated text: Previously, since the Adventure Update, all types of swords could be used to parry to block some forms of damage. If the player is blocking with a sword when attacked, the sword deflects 50% of incoming damage from melee, non-magical projectiles like arrows, and explosions, along with minimizing knockback. The sword is held in front of the player and its durability is not reduced by blocking. The player moves at a slower rate than sneaking if blocking with a sword. Sword blocks could be engaged and disengaged instantly, with no delay between the input and damage mitigation nor cooldown between lowering a block and raising a new one.