A complication can arise if Black has moved his king into the corner, making room for his rook on g8. Thus in the position shown here White still would mate if his queen now were at g7—but it will take him two moves to get it there, and in the meantime Black can protect the mating square with Rg8. Yet if White has another heavy piece available he still can finish off the king. Here White plays 1. Qh6, inviting—requiring, really—Black to go ahead with Rg8. But then White sacrifices his queen with 2. Qxh7+, KxQ—and now 3. Rh1 is checkmate. Black’s own rook prevents his king from retreating to g8, and White’s pawn on f6 seals off g7 in the way a bishop might. This maneuver, one of a few patterns known as “Lolli’s mates,” was published by Giambattista Lolli in the 1700s.