Historical Rules · 18 June 2021
Rule 805.4d
Official source text from the 18 June 2021 Rules release
An ability that triggers at the beginning of a step or phase may trigger multiple times if it triggers at the beginning of “each player’s” or “each opponent’s” step or phase. These abilities trigger once for each appropriate player if the ability’s trigger condition, effect, or intervening “if” clause refers to “that player,” “that opponent,” or similar.