Challenge mode
You can duel with your friends in the checkmate server.
You and your friend have both to be in the waiting room.
Let's suppose that there are two players in the waiting room: player1 and player2.
Player1 types in the chat "!challenge player2",
player2 clicks on [X]ACCEPT to accept the challenge.
Other valid commands are:
!challenge MATCH player2
!challenge TAG player2
!challenge HANDICAP player2
Change duel settings
When you enter the checkmate server, click on the "Duel" button before clicking anything.
You will be redirected to a page where you can change banlist and duel mode.
The default duel mode in SINGLE.
Handicap match
You can play 1vs2 or 2vs1.
To enter the handicap match mode, change the duel mode until you see [X]HANDICAP.
Inside the handicap match room, click on the "Duel" button to switch teams
Always online
The checkmate server is a cluster of servers. When you join, you will be redirected to the fastest available server automatically.
While one of the servers in the cluster is offline or is updating, the others will be always available.
Each server is identified by its PID, the server will tell you its pid in the chat box when you login.
PM feature
While you are in the server you can send a private message to other users.
To send a PM, type "!pm player2 yourmessage" in the chat box
Available to all ygopro flavors
You can connect to the checkmate server with all ygopro clients, for example ygopro percy, devpro, TDOANE, ygocore...
If you are using a unsupported server, follow this tutorial to understand how to enter the server:
http://ygopro.it/web/modules.php?name=Tutorials&t_op=showtutorial&pid=3
Subject: Commands to invite players to a checkmate server 
