GDUELS EU is a regular Half-Life 2: Deathmatch server running a custom match plugin (match_core) -- there's nothing to download or install beyond the game itself. Connect through Steam with the button below, or paste the IP straight into your in-game console.
Once you're in, join a team from the team menu -- you can't start or join a match while sitting in spectator. If a match is already running, you can still spectate it freely; you just won't be part of the roster until the next one starts.
Any player who isn't spectating can start a match with !run <preset|map>, as long as nothing is already running.
!run also accepts a map name directly instead of a preset -- a short alias (like biohazard) or the full map name both work, and it'll switch straight to that map.
!balance (alias !b) looks at the players currently on each team and suggests a more even split before a teamplay match starts. Worth running any time teams look lopsided going into a match.
!sub pauses the match for you if it isn't already.!vs) Opens a menu to vote a player to spectator. Only usable when no match is currently running.If someone disconnects mid-match, the rest of the roster will usually get an automatic vote prompt to bring in a sub -- !y / !n in chat answers it, same as clicking the menu option.
!votecancel) Cancels the match outright and removes it from the database entirely -- use this for accidental starts, not for a match you actually want on record.Every finished match is recorded automatically -- no need to do anything extra. Elo updates for everyone involved (1v1, team and free-for-all matches are all scored correctly), and the full breakdown -- kills, deaths, headshots, accuracy, weapon usage, and a downloadable demo if one was recorded -- shows up right here on the tracker within a few moments of the match ending.
Your rank badge (Bronze through Pro) is based on your Elo and updates the same way. You can see the full breakdown any time on your player profile, and browse every match played on the server under Matches.