The Era of Four Moons is an expansion for Battle for Wesnoth (an open-source turn-based strategic wargame), that is loosely based on the 'medieval' period of Ialfa history. The Era was coded by Velensk, (noted in the Wesnoth community for the excellent gameplay quality of his various add-ons,) and the additional art was provided by me. (You can take a look at the art without actually playing the game, by going to the Four Moons Sprites Page.) The expansion was designed for an interesting and balanced playing experience, rather than for absolute accuracy to my world, and does not use any Ialfan names or terminology.
The Era of Four Moons
In order to play you first need to download and install Wesnoth itself. The banner above will take you to the Wesnoth site, so that you can do that. Once you have it running, click on the button on the sidebar marked "Add-ons". It will tell you it wants to connect to the server. Hit "Connect". Wesnoth will now download the list of available add-ons. Unless you want to do a LOT of scrolling you should type "Era of Four Moons" into the box labeled "Filter". Click on the Era and then click "Okay" (at the bottom right). Wesnoth will now install the Era of Four Moons.
Once the Era is installed you can start a game against the computer by clicking on "Multiplayer" in the sidebar. Type in your name, then click "Local Game" (last choice on the list). A "Create Game" screen will appear. On the bottom left under the word "Era" will be a button marked "Default". Click on that button and select Era of Four Moons. Next you need to choose a map. Velensk recommends "Den of Onis" as a good two player map for a beginner. You probably want to leave all the other settings on their defaults and click "Okay". On the next screen you set up your players. One should be you, and the other should be set to "Computer". (Unless you have a friend around who wants to play with you on your computer.) Choose your faction and your team color and you're good to go.
Wesnoth is a sophisticated game with a well established base of players, and a mature rule set. Learning the basics at least well enough to be able to beat the Computer Player in a one-on-one engagement, is strongly recomended before joining the server and starting up any PvP matches there.
If you don't want to play multi-player, Era of Four Moons does have two single-player campaigns available, a small introductory level campaing called Salt Wars, and a large expert level campaign called The Panther Lord.