At Global Tennis Network, we regularly get asked "what are the rules of a tennis ladder." There are actually no set rules to a tennis ladder. A tennis ladder is just a way of ranking players based on the matches they have played. The goal to to be at the top of the ladder. Think "king of the mountain". How players are ranked depends on what ranking system is used.
At Global Tennis Network, we allow you to create a tennis ladder, and choose the ranking system you want to use. The most common of which is the classic "Leap Frog" system.
On the Leap Frog system, if a lower ranked player on the ladder, beats a higher ranked player, then the lower ranked player jumps up on the ladder to the position of the higher ranked player, and the higher ranked player drops one position.
There are also ranking system that award points for each match played. The more points a player has, the better the player will be ranked on the ladder.
Along with the rankings system, you may need other tennis ladder rules. For example, how far up or down your players can challenge other players to a match. Or how to penalize players for being idle. You may even have penalties for declining a challenge.
Check out all the available ladder rules on this page where you would create a ladder:
https://www.globaltennisnetwork.com/tennis-ladders/start-a-tennis-ladder