One or more stun counters on a permanent create a single replacement effect that stops the permanent from untapping. That effect is “If a permanent with a stun counter on it would become untapped, instead remove a stun counter from it.”
September 8, 2022 · Dominaria United
A stun counter on a permanent creates a replacement effect that stops the permanent from untapping. That effect is “If a permanent with a stun counter on it would become untapped, instead remove a stun counter from it.”
April 29, 2022 · Streets of New Capenna
The number of loyalty counters on a planeswalker on the battlefield indicates how much loyalty it has. A planeswalker with 0 loyalty is put into its owner’s graveyard as a state-based action. See rule 704.
April 17, 2020 · Ikoria
If a player has ten or more poison counters, that player loses the game as a state-based action. See rule 704. A player is “poisoned” if they have one or more poison counters. (See rule 810 for additional rules for Two-Headed Giant games.)