Night falls: every knight, bishop, rook and queen on the board (both sides) sleeps and cannot move for 2 turns of its owner. Kings and pawns keep watch.
You draft The Big Nap in Buff mode. Instant: it takes effect the moment you draft it.
As a tempo card, it buys time: an extra move, a skip, or a freeze.
“History's greatest armies, defeated by a warm blanket.”