What is a chaos counter in yu gi oh?

Answer 1

Counters are markers placed on a card, different cards place different types of counters. Counters themselves have no effect unless given one by a card, and that card tells you what it does. Spell Counters are the most common type, and what they 'do' depends on what they are on. Because there are many cards that can place counters, they all have different names, so they don't get mixed up with each other.

The card Chaos Zone places counters on itself, and these are called Chaos Counters. The only thing they 'do' is that they can be used for Chaos Zone's other effects. Other cards could potentially place different kinds of counter on Chaos Zone. Magic Reflector places a counter on it - this could not be used for Chaos Zone's effects as it is not a Chaos Counter, which are only placed on Chaos Zone by itself.