Gaming over VPN
From DD-WRT Wiki
Setting up a private secure network between you and your friends for things like easy file transfer and lan gaming is something a lot of people want to do and now DD-WRT can help you with that.
Hamachi is plug and play VPN, this is probabaly the easisest method of creating a VPN to play games. This is only noted to let you know it exists, you do not require DD-WRT to use it. For more information visit: https://secure.logmein.com/products/hamachi/vpn.asp
How to configure PPTP to play lan games
- Configure the PPTP Server on DD-WRT
- Ensure you enable Broadcast for VPN clients as most games use broadcast for their LAN game browsers
- Configure your PPTP Clients
- Change the Access order of the VPN connection to make it the highest as this can effect many games
Thats it, have fun gaming!
Create a openvpn bridged network (router to router or client to router) tunnel.
 Ethernet Over IP Tunneling
Creating an EoIP Tunnel is effectively similar to Hamachi (Joins 2 private/personal networks across the internet) without the need for installing resident software on your PC. Unfortunately this requires support from both ends, as each router must be configured to use EoIP. See EoIP Routing for more information.
 Specific Game Troubleshooting
The Hamachi wiki already has a good list of games and how to configure them for VPN access, see: http://logmeinwiki.com/wiki/Category:Gaming