The Labouchere System is a betting strategy often used in games like roulette or craps. It involves creating a sequence of numbers that represent the desired profit. Players bet the sum of the first and last numbers in the sequence, adjusting the sequence based on wins or losses. If a player wins, they remove the first and last numbers from the sequence. If they lose, they add the amount of the lost bet to the end of the sequence. The goal is to eventually eliminate all numbers, achieving the desired profit.