How does Whirlwind the spell work in 1v1 and 2v2 scenarios?

Whirlwind functions identically in both 1v1 and 2v2 scenarios regarding its core mechanics: it does not target, and it relies on players making choices during resolution.

How Whirlwind Works

According to RiftJudge FAQ #3563 and #548, Whirlwind works as follows:

1. No Targeting: Whirlwind does not target units. Because it does not target, it does not trigger abilities like Deflect (see RiftJudge FAQ #3908 and #4619) and can affect units with protection from enemy spells and abilities, such as Ruin Runner (see RiftJudge FAQ #548).
2. Resolution: When Whirlwind resolves, starting with the next player in turn order, each player makes a choice.
3. The Choice: Each player may choose any unit on the battlefield to return to its owner's hand. The "may" is included so that players are not forced to return their own units if there are no other valid targets available (or if they simply choose not to).
4. Player Choice vs. Spell Choice: Because the players are the ones making the selection during resolution, the spell itself is not considered to be "choosing" or "targeting" the units.

1v1 vs. 2v2

• 1v1: The turn player (the one who cast Whirlwind) and their opponent each get to make a choice in turn order.
• 2v2: In a 2v2 match, the turn order follows the sequence defined in Rule 603.7.a (Team A Player 1, Team B Player 1, Team A Player 2, Team B Player 2). Each player in that sequence will have the opportunity to choose a unit to return to its owner's hand when Whirlwind resolves.