Does Consecrated Sphinx trigger during your own draw step or only from opponent effects?

Consecrated Sphinx reads: "Whenever an opponent draws a card, you may draw two cards." The trigger condition is specifically tied to an opponent drawing a card, so your own draws — including your normal draw step — never trigger it (CR 603.1, 603.2).

During your own draw step, you draw a card as a turn-based action (CR 504.1), but since you are drawing, not an opponent, Consecrated Sphinx's ability does not trigger at all. It is completely irrelevant who caused the opponent to draw — it fires on any opponent draw, whether from their draw step, a spell like Ancestral Recall, or a card effect.

When an opponent does draw a card, Consecrated Sphinx's triggered ability goes on the stack and you may choose to draw two cards (CR 603.3). The "may" means you can decline if drawing would be harmful (e.g., to avoid milling yourself).

Concrete example: It is your opponent's turn. They draw their card for the turn (CR 504.1). Consecrated Sphinx triggers, and you may draw two cards. Later on your turn, you draw your card for the turn — Consecrated Sphinx does not trigger because you are not an opponent of yourself.

In multiplayer games, the sphinx is especially powerful because each of your opponents drawing cards — even during their own draw steps — triggers it separately, potentially letting you draw enormous numbers of cards (CR 603.2).