Many games identify players by their Steam ID: Rust, Valheim, 7 Days to Die, Project Zomboid, Palworld, DayZ and more. You need it to make someone admin, to ban them, or to add them to a whitelist.
The format game servers want is the Steam64 ID: a 17-digit number that usually starts with 7656, for example 76561198000000000. Older formats such as STEAM_0:1:12345 or [U:1:12345] will not work in most server files.
From the Steam app
- In Steam, click your name at the top right and choose Account details.
- Your Steam ID is shown under your account name. Copy the number.
From your profile link
Open your Steam profile in a browser. If the address looks like steamcommunity.com/profiles/76561198000000000, the number at the end is your Steam64 ID.
If it looks like steamcommunity.com/id/yourname, you have a custom profile link. Paste that link into a Steam ID lookup site such as steamid.io and copy the steamID64 value. Do not remove your custom link to see the number; someone else could claim it.
Another player’s ID
Ask them to send it using the steps above, or paste their profile link into a lookup site. Many games also print the ID in the server Console when a player joins or tries to join, which is often the quickest way.