On a phone? Watch the vertical version (9:16)
Steps
Open the link your organizer shares
Your organizer sends you the tournament page. Open it in a browser on your phone or computer. Tournament chat runs on the web, so there is nothing to install. The page shows what is open: a Register button appears once registration is open, and Join the chat appears when the chat is on and open to everyone. If you see neither, ask your organizer.
Register for the tournament
Scroll to the registration card and tap Register a player. On a team tournament the button says Register a team. If a Team registration page says this is a solo competition, tap Continue with entrant registration. Sign in or create a free EasyChamp account and fill in what the organizer asks for, such as your gamertag. If the organizer requires a verified Discord, connect it, and Register as entrant turns on. The organizer may review your request before you are in.
Get into the chat
Once the organizer accepts your registration, you have player access to the chat. If the tournament page shows Join the chat, tap it. If it doesn't, ask your organizer for the chat link and keep it, because tournaments don't show up under Club chats yet. Anyone can also use Join the chat without registering, as a fan. Fans don't get match rooms and usually can't attach images, and by default a new account has to be 24 hours old before a fan can post.
Read #announcements, then say hello
Start with #announcements, where only staff post. Say hello in #general, and use #find-your-opponent to look for a game. Your organizer can add more channels, so the list may differ.
Tag people with @
Type @ in the message box and pick a name. They get a badge on the channel, so they see the message meant for them.
Use your private match room
Your game has its own room for both sides and the tournament staff, unless the organizer turned rooms off. Find yours under My matches in the chat. Agree a time, swap in-game ids and post the final screen there. You can attach an image with the image button, or paste or drag it into the message box (JPEG, PNG or WEBP, up to 15 MB).
Submit your result
On your screenshot, tap Submit as result, check the score and send it for approval. The other side can confirm it with one tap or report a different score. The organizer approves it, and only then does the result go live and update the standings.
Running the tournament? See the organizer guide to tournament chat.