Block

Blocking allows a character to stop an attack that was about to hit from hitting. Guildwars offers many Blocking skills:
 * Elementalist: Magnetic Aura (blocks melee attacks only), Swirling Aura (blocks ranged attacks only).
 * Mesmer: None.
 * Monk: Guardian, Aegis
 * Necromancer: None.
 * Ranger: Whirling Defense
 * Warrior: Wary Stance, Shield Bash, Riposte, Deadly Riposte, Gladiator's Defense, Bonetti's Defense, Shield Stance, Disciplined Stance, "Shields Up!" and Deflect Arrows (blocks only ranged attacks).

Note: Spells cannot be blocked, though spell projectiles, like Flare, may be blocked.