Blocker

Blocker is an evergreen keyword shared between the Light, Water, and Darkness civilizations.

Details
Whenever one of your opponents creatures attack you or one of your creatures, you are able to tap one of your creatures that has the "Blocker" ability to be attacked instead, blocking the attack. The two creatures then battle.

There is only one mono-colored creature with the Blocker ability that exists in the Nature Civilization, Supernova Bigbang Anastathis. This is likely due to it evolving from 2 races shared by the Light civilization.

Note that being a blocker is not always a good thing to creatures as sometimes it makes them more susceptible to Blocked based removal.

"Diamond State" cards can allow creatures that have Blocker and cannot attack players or attack at all to attack.

This ability has a weaker variant on Fire and Nature creatures, Guardman.

Blockers by Civilization
 * Light — Has the most amount of creatures with the ability. Their creatures often can't attack players.
 * Water — Their creatures often can't attack at all.
 * Darkness — While creatures that have blocker are less numerous, they often have the Slayer ability as well. Some also have higher than usual power, but are destroyed when they win a battle. A few are able to still attack, but feature low power.

Reminder Text
The latest reminder text for Blocker reads;

Example
 La Ura Giga, Sky Guardian
 * Light/Creature/Guardian
 * 1/2000
 * [[file:blockericon.jpg]] Blocker (Whenever an opponent's creature attacks, you may tap this creature to stop the attack. Then the 2 creatures battle.)
 * This creature can't attack.

Cards with the Blocker ability
Creatures
 * -|Light=
 * -|Water=
 * -|Darkness=
 * -|Zero=
 * -|Multicolored=

Other Creatures
 * -|Dragheart Creature=
 * -|Evolution Creature=
 * -|Exile Creature=
 * -|Psychic Creature=

Cards that give creatures Blocker

 * -|Spell=
 * -|Castle=

Support
Cards that support creatures that have Blocker

Cards that support Light civilizations creatures that have Blocker

Cards that evolve on creatures that have Blocker

Anti-Support
 * See also: Cards that destroy creatures that have Blocker.

Rulings

 * Q: Can I block with a creature the turn after it is summoned?
 * A: Yes. Blocking is not affected by summoning sickness.
 * Q: Can a tapped creature block?
 * A: No. The blocker must be untapped in order to block.