There are no such rules in AYSO to deal with games where one team is dominating the scoring. In any competition, there is the chance that the score will be lopsided.
We believe such things as rules designed to:
Only penalizes a team for accomplishing what it has been trained to accomplish (score goals) and sends the wrong message to the losing team.
A major part of sport is enjoying the process of playing by the players - not just who ultimately wins. The message we want to send is "keep on trying" - not to give up just because it is difficult. Losing, when dealt with appropriately, builds character and resolve to improve. Mercy Rules, play short rules or similar such rules potentially build a willingness to give up early or to want rules in place to give teams an unfair advantage just because they are losing.
Each team is entitled to start and play the game with the maximum number of players allowable. Nowhere in the Laws of the Game or in the AYSO National Coaching or Refereeing Program is it suggested or required to have a winning team play with fewer players that the losing team or for the game to end early or similar rules because the score is lopsided. The AYSO "Balanced Team" concept refers to making an honest attempt to balance the skill level of teams within an age group when teams are formed prior to the beginning of the season.
In situations where one or both teams are short a significant number of players, a "friendly match" could be organized by combining/sharing players from one or both teams. Where won/loss standings are recorded, the outcome of the "friendly match" would not affect the standings. It should be predetermined and agreed upon in advance how the official outcome of the regularly scheduled game is to be recorded. Regions should not adopt local rules and referees should not interfere with games because of lopsided scores. It is a player's game and they should be given the full playing time without undue interference to enjoy and learn from the process.