See you in Crossfire . Watch for the toilet.
: The game frequently goes on sale for a significantly lower price, sometimes as low as $1.00. Free with Other Purchases
: Non-Steam versions cannot connect to official Valve Anti-Cheat (VAC) secured servers. Players are often relegated to a small handful of unofficial servers which may have their own security vulnerabilities or lack active player bases. Broken Functionality
💡 When searching for free downloads, be extremely cautious. Unverified "free" installers are common targets for malware and adware.
Half-Life Deathmatch: Source (HLDMS) is a Source engine port of the original Half-Life multiplayer.
Source isn't available on Steam, how can I get and play it? : r/HalfLife
Technically possible, practically useless for actual multiplayer.