Leveling in poker is the strategic concept of adjusting your reasoning to be one step ahead of your opponent. The basic levels include: thinking about your own cards (level 1), thinking about the opponent’s cards (level 2), thinking about what the opponent thinks you have (level 3), and so on recursively. The goal of leveling is to identify which level your opponent is thinking at and make decisions optimized against that specific level. GTO theory argues that equilibrium strategies are superior to leveling because they eliminate the need to guess the opponent’s thinking level.