XYZ-Wing

XYZ-Wing is Y-Wing with one extra candidate on the pivot. Now the pivot holds {X, Y, Z}, while the two bivalue wings still have {X, Z} and {Y, Z} and both are peers of the pivot.

Whichever digit the pivot becomes (X, Y, or Z), Z lands in one of the three cells — pivot or a wing. Any cell that sees all three of them cannot be Z. The elimination zone is smaller than Y-Wing — you need a cell that sees pivot AND both wings — but otherwise the reasoning is identical.

When the move applies

Watch for a trivalue cell that's a peer of two bivalue cells whose candidate sets together cover the trivalue's three digits.

The procedure

1. Find a trivalue cell P with candidates {X, Y, Z}.
2. Find two bivalue peers, W1 = {X, Z} and W2 = {Y, Z}.
3. Eliminate Z from any cell that sees P, W1, and W2 all at once.

On a small board