Author and test GameLift FlexMatch rule sets for skill-based team matchmaking

Steps

1. Define a FlexMatch rule set in JSON specifying teams (name, minPlayers, maxPlayers) and a list of rules; store it in the GameLift console or via the AWS CLI CreateMatchmakingRuleSet command.
2. Add a latency rule using the latency rule type to ensure all matched players have acceptable latency to the selected region; specify a maxLatency value and reference the latencyMap in player attributes.
3. Add a distance rule on skill rating to keep player MMR values within a defined distance of each other; use the distance rule type with an expression referencing a player attribute key.
4. Add an absolute sort rule or batch distance rule on team composition if balance between teams is required (e.g., average team skill within a threshold of the opposing team's average).
5. Use the ValidateMatchmakingRuleSet API to check the rule set JSON for syntax errors before deploying, then associate the rule set with a matchmaking configuration.
6. Use the StartMatchBackfill API in your game server to fill open slots mid-match; include the existing players' attributes and the current match ID so FlexMatch avoids placing duplicate players.