Guard

Guarding is Kirby's only defensive action in games such as Kirby Super Star, its remake, and Kirby's Return to Dream Land. By holding down the guard button, Kirby assumes a defensive posture until the button is released. While guarding, Kirby takes no damage from weak attacks and minimal damage from stronger attacks, in addition to retaining his ability and not getting knocked off the ground. Enemies that contact a guarding Kirby also take minimal damage.

Generally, guarding is ineffective against attacks which involve grabbing. Guarding also has no effect on environmental elements such as wind or lava. Kirby can only guard while standing still.

Abilities with Special Guards
Ice - In Kirby's Return to Dream Land, guarding with Ice produces a spherical ice formation around Kirby which blocks more damage than a regular guard.

Leaf - In Kirby's Return to Dream Land, while guarding with Leaf, Kirby is intangible instead of invincible; attacks will simply pass through him regardless of their power. This guard also makes Kirby immune to grabs. Releasing the guard causes minor damage to nearby enemies.

Mirror - In Kirby Super Star and Kirby Super Star Ultra, guarding with Mirror provides a shining bubble of energy around Kirby's body. This bubble negates damage from even strong attacks and can reflect projectiles.

In the Super Smash Bros. Series
The shield mechanic in the Super Smash Bros. series is heavily based on the guard mechanic, with the energy bubble very reminiscent of the Mirror ability's Reflect Guard. The primary difference is that shields shrink as they are held or take damage and will eventually break if not deactivated, stunning the user. {-}