Subnetting > Router IP Address

I was doing a subnetting exercise (on Cisco's Subnetting Game) and it asked about a Router IP Address. I realize that the router has an IP address in order to act as a default gateway for the subnet, but what are the stipulations? In other words, how do you determine the router's IP address.

Thanks in advance.

The simple answer is the administrator will determine the routers ip address. So it the subnet 192.168.1.0 /24 you have 254 address available. 192.168.1.0 is reserved as the network address and 192.168.1.255 is the broadcast. The router could be assigned any address in between to act as the gateway. That being said, most of the time the first address of a subnet will be the gateway.