Ratings and game rules

When your rating moves, and how a game can end. The numbers below are the ones the server plays by.

Rating

Ratings are separate per rule and time. A base time of 3 minutes or less is blitz, up to 10 minutes is rapid, and anything longer is classical.
A new rating starts at 1500. It is Glicko-2, so a result further from what was expected moves it further.
While a rating is still unsettled it is shown with a "?". More games settle it.
A rating joins the leaderboard after at least 30 games in that pool, once it is settled enough.
Beside a rating you may see a margin, written ±80. It is how certain the rating is: the lower it is, the more settled, and it falls the more you play. Ranking asks for a settled rating for the same reason it asks for 30 games — a number nobody is sure of is not a position.
Both players are rated for the same game: a win scores 1, a draw 0.5, a loss 0.

Five in a row: The first player to line up five wins.
Resignation: You may resign at any time; your opponent wins.
Draw agreed: One side offers, the other accepts. An offer is cleared by the next move.
Full board: If the board fills with no five, the game is a draw.
Time out: Whoever runs out of time first loses.
Abort: Either player can abort while the game has at most 2 moves, and a game aborts itself if the first two moves do not arrive within 30 seconds. An aborted game leaves no rating and no record.
Opponent left: If your opponent disconnects, you can claim the win once the grace period has passed.
Black has no legal move (renju): In renju, black loses when every empty point left is forbidden.

A move costs the time it took and then adds the increment.
Some network delay is given back: up to 500ms in blitz, up to 1000ms otherwise.
The server decides a time out, so a game ends on time even if nobody is watching.

The grace period is 20 seconds in blitz, 45 in rapid and 60 in classical. Coming back inside it simply continues the game.
After it passes, the player still there can end the game with "Claim win".
Clocks keep running either way, so a player who left while on move loses on time.