What happens if a player has 10 or more poison counters?

When a player accumulates 10 or more poison counters, they lose the game. This rule is specific to the poison counter mechanic introduced in the game, which operates independently of the traditional life total system. The concept behind poison counters is to present an alternative win condition, where the accumulation of these counters signifies a player's defeat, rather than reducing their life total to zero.

This mechanic is often associated with certain creature abilities and spells, particularly in formats featuring toxic creatures or abilities that inflict poison. When a player receives their 10th poison counter, the game immediately recognizes this status, and that player is declared the loser, regardless of their life total or other game states.

The other choices do not align with the rules governing poison counters. There is no passive effect associated with just having poison counters that would allow the player to continue playing or gain benefits such as card draws or the transferring of counters, nor does having 10 poison counters lead to any other outcome except a loss. This makes the identification of the loss condition clear and straightforward within the comprehensive rules of Magic: The Gathering.