[Multiplayer] Why do matchmaking docs hint it 100% "creates" a server rather than also join? I am a bit confused

Ok, quick clarification :

Matchmaking in the API is a bit of a misnomer, because it actually merge both server listing and matchmaking under that same name.

The sample is a very basic one that only use the server listing one : you create a match, which get registered into Unity Multiplayer service server, so that other can query that server for currently existing matchs and get a list of those. Unity server then take care of linking the two computers.

Now, you can't have a one solution fit all for matchmaking, as it is highly dependent to your game (you need a way to give a "skill score" to your player depending on how well they do in your game, which in turn depend to what your game is about). Unity use the Elo rating system (https://en.wikipedia.org/wiki/Elo_rating_system)

The way to do a "League of Legend" matchmaking system would then be :

• compute a Elo score for your players (no idea how to, kill/death ratio, number of game won etc..)

• When that player click on "Find match"

  • use the eloScore parameter into the matchmaker ListServer function

  • check the eloRating of the highest matchs (the closest match), now

    • if that rating is close enough to the player's rating, make him join the match

    • if the rating is too far OR there is no match return, create a match throught CreateMatch, given the player elo score as the server elo score