Counters are markers placed on cards or players to modify characteristics or track resources and effects. Counter decks deliberately produce and manipulate these markers, including everything from +1/+1 and loyalty counters to poison, charge, and many more specialized varieties.
The Ozolith can preserve counters from creatures that leave the battlefield, while Resourceful Defense moves counters between permanents. Proliferate effects provide an especially flexible way to increase several different kinds of counters at once.
