"ARENA Online" is an MMORPG based on RvR warfare. There are three races/factions to pick from: Nordic, Elvish, and Human. Unlike many MMORPGs, "ARENA" doesn't feature classes, but instead utilizes a skill-based system, requiring a greater amount of variety.

Skills are split into two basic categories: Fighting and Crafting. In Fighting, players can learn various types of magic, archery, and swordfighting; Crafting includes skills ranging from traditional ones such as lumberjacking and metallurgy, to more unique ones such as Discount (gets you a better deal purchasing from NPCs) and Overcharge (gives you more money when selling items).

Two regular events in the game are Castle Sieges and Treasure Chest Hunts. Sieges can occur at any time of the day, and guilds can attack, conquer, and then must defend one of four castles against other players. Treasure Chest spawns occur multiple times throughout a day, and by fighting the chest and other players, players can win various rewards, including platinum coins.