1.first find out what port your game is using

2.type 192.168.1.1 in your web browser

3. click on the advanced tab

4. click on the fowarding tab

5. on the farleft type a name to keep track of the rule

6.under ext port type the port for example but not the numbers that you will use in your case (80 to 80 or ports 80 to 85)

7.Check the protocal the game will be using(more than likeley tcp)

8.Enter the ip adress that the router assigns the machine you are setting this up for usually if its in port 1 its 192.169.1.100 but that isint always true.To find this if you are running xp or 2k open run and type cmd then type ipconfig. For 98 and the like open run and type winipcfg

9.lastly check the enable filed to set activate it.