Combat events in Avilion are called "Call to Arms" (or CTA).
Combat in Avilion is different from combat in most other sims: when we combat, we usually make two or more mixed teams, who engage in an event combined of fighting and a game,. The winner is usually decided by who wins the game.
The game element makes the CTA more fun. They come in many forms. One example is a gathering game where you have to gather an item and bring it to a chest. Each team has their own chest but while gathering, you can be attacked by the other team (or teams). Another example, one that is used often, is a beacon game. This is where you have to "conquer" a beacon by staying close to it for a fixed amount of time, and while you are conquering, you can, of course, be attacked.
Fighting is most never one race against another, or one combat class against another. The combat is not a part of an ongoing "war" or friction between factions in the community, the only exception being within a roleplay story.
This is because, long ago, Lady Serenity and Lord Malakh, the founders of Avilion saw that this way of doing combat strengthened the community instead of splitting it in several factions. So in Avilion, combat events are not "real" combat but training events, calling the fighters of our realm to gather, train and test their skills, so they will be ready when Avilion needs to be defended.
Avilion use the ACS combat system. You can get the free meter and HUD from Nexus as well as free demo weapons. These weapons look basic but function the same as all ACS weapons except the magi and druid staffs.