Server Access

• Public: Shown on the server list and anyone can join
• Friends-only: Not shown on the server list but people can still join:
  • Via the lobby id
  • If they are friends with or invited by someone who is in the lobby
  • Someone in the lobby has their "Game Activity" in their steam privacy settings set to "Public" and someone joins via their profile
• Invite-only: Not shown on the server list but people can still join:
  • Via the lobby id
  • If they are invited by someone who is in the lobby

Server Password

You can specify a password which will be required no matter what the "Server Access" is set to.

Enabling this option requires all clients to have the mod!

Validate Steam Sessions

This option allows you to force all players to have a valid steam session, if the session becomes invalid then they will be kicked. If you are unaware of what session tickets are, here is a summary taken from the Steam Docs:

Session Tickets are signed tickets that can be used to verify a user's identity between the user's game client and the lobby host. These tickets can also be used to verify ownership of the current game and related downloadable content, and determine if the user has been VAC-banned.

Enabling this option requires all clients to have the mod!

Max Players

To be able to modify the max player count you must have MoreCompany.

Setting this above 4 requires all clients to have the MoreCompany mod!