Gravity Zero

Gravity Zero (also known as G Zero) is a keyword for creatures that features in each of the 5 civilizations.

Creatures with the Gravity Zero keyword can be summoned into the battle zone for no cost if certain requirements are met.

Reminder Text
The latest reminder text for Gravity Zero reads;

 "If there ____________, you may summon this creature without paying its cost."

Example
  Valkerios Dragon 
 * Fire/Creature/Armored Dragon/7/6000
 * Gravity Zero — If there are 2 or more Armored Dragons in the battle zone, you may summon this creature without paying its cost.
 * Double breaker

Cards with the Gravity Zero ability
category=Gravity Zero uses=Template:Cardtable

Rulings

 * Even if the requirements of the Gravity Zero is met, the creature can still be summoned for its usual cost. (This is important against cards such as Magnum, Allshot Puppet)
 * You can only use the Gravity Zero ability of creatures at the same time you may regularly be able to summon a card, during the Summon and Cast step of your turn and before attacking.
 * A card that reduces the cost of a card says that "They can't cost less than 1" does not affect cards with Gravity Zero. They may still be played at a cost of 0.

Color percentages
 There are a total of 21 cards with the Gravity Zero ability, which divide by civilization as such:
 * = 19% (4/21)
 * = 10% (2/21)
 * = 24% (5/21)
 * = 29% (6/21)
 * = 14% (3/21)
 * Multicolored = 5% (1/21)