The DCI (Duelist Convocation International) is an organization that creates standardized rules for play and tournament reporting procedures. Playing in sanctioned League events allows you to compete on the world stage by earning worldwide ratings. You get to see exactly where you stand against other players and, in the future, ratings may be used to issue invitations to Championship events.
Ask your local store if their events are sanctioned. It's not much harder than running a normal tournament and the store can report results online. To sanction their tournaments, stores should contact Wizards of the Coast by email at DCI@wizards.com.
By playing in sanctioned events, you will affect your own individual DCI rating and can change your ranking in your local area and the world. For some Championship events, higher ratings can earn you invitations.
To look at your personal statistics, make sure you have your DCI number handy. If you do not have a DCI number yet, simply participate in any sanctioned tournament and the organizer will provide one for you for free.
Running DCI-sanctioned tournaments is a great service you can offer your players, keeping them involved in organized play at your location for a long time to come.
The DCI creates standardized rules for play and tournament reporting procedures so your players know what to expect when they attend your tournaments. DCI sanctioning also allows them to build ratings and rankings, which gives them local prestige and the possibility of taking their play to the highest levels.
The DCI uses the Elo rating system for most games it supports. This method of calculating player ratings and rankings allows players to gain or lose points based on the strength of the opponent they are facing. For more information about the Elo system, please refer to Appendix A of the Universal Tournament Rules.
To sanction your tournaments, contact Wizards of the Coast by email at DCI@wizards.com.