What is a double check in chess?

What are Double Check and Discovered Check in chess?

Chess 101: What Is Double Check? Learn How to Perform and Respond

Consecutive double-check records in problems

chess double check

WHY IS DOUBLE CHECK DANGEROUS ?

Double Check III

Double Check ! (Checkmate Pattern You Must Know!) in 2023

Double-check

Apparently, someone thinks a discovered double check winning a pawn and a rook ain't the best move (Please help) : r/ChessPuzzles

In order to win you should always double check chess design