Game ladders are a way of ranking players. The ladder system is
based on the principle of rungs - winning games moves you up the
rungs of the ladder and losing games moves you down. When you join
a ladder you are automatically entered at the bottom. Your goal
is to climb your way up the rungs until you get to first place.
When you defeat a higher ranked player you move up half the
distance between their rank and your own. The higher player that
lost will move down one rung. When other players beat people above
you and jump over you in rank, you will move down.
Here's an example: Tad is ranked #10 and Sheryl is ranked #40. If Sheryl defeats Tad, Sheryl moves up to rung 25 (because 25 is halfway between 10 and 40), and Tad moves down to rung 11. The players who were at rungs 25-40 each move down one to make room for Sheryl. The player who was at rung 11 will move up to rung 10 to replace Tad.