What games would you suggest that have LAN support these days?
While PC may be one's first thought here, I'd also be really interested in any mobile games that might leverage one's local wifi network for multiplayer.
Classics FPSes included Unreal Tournament 2004 and Quake 3. Both scale from 1 on 1 to 16 players well, meaning days of fun. Xonotic the open source clone, which is also very good
Worms is a hoot, can hotseat or LAN, armageddon I think the high point of the series. Hedgewars a more than worthy OS reimagining
RTSes are soo many, Warcraft 3, C&C series, or Total Annihilation all modded, all great. My choice is Balanced Annihilation or OpenRA for 2023 and OS
4X have classics like civ, but Stellaris a worthy choice too. Open source here includes unciv
Racing games are often a hoot too. You can get far too serious here if you want, but I recommend SuperTuxKart for some mariokart like action
Scorched3d another option for artillery fun. But generally Open Source all offer LAN gaming!