A false H4 is a common tactic in chess where a player makes a surprising move with a pawn to slide onto h4, intended to catch the opponent off guard. This strategic move can serve to exploit openings or expose weaknesses in the opponent's defense line. The aim is to set a trap, sow confusion, or force the opponent to change their plans. While it's not a guaranteed winning move, it can be effective in the hands of an experienced player who knows how and when to apply it.