The multiplayer servers were shut down by Atari years ago. RePacks strip out the dead online components, saving space and removing error messages that would otherwise pop up when trying to access the multiplayer menu.
While RePacks are often associated with piracy, many are legitimate archival releases. The game is abandonware —Atari no longer sells it on Steam, GOG, or any digital storefront. No money goes to the developers if you buy a second-hand disc. If you locate a from a site like MyAbandonware or Archive.org, you are preserving video game history. However, always scan files with VirusTotal and support official re-releases if they ever happen (unlikely, due to music licensing). Dead Man-s Hand PC Game -RePack-