Castle Wars is a combat-based members-only minigame which was released by Jagex on 13 December 2004. It is similar to Capture the flag, but with a RuneScape twist. In January 2009, Castle Wars was selected as the most popular player-versus-player minigame in a poll.

Castle Wars is found in the south-west corner of Kandarin and may be accessed via a number of ways:

Using a Ring of duelling to teleport directly to the Castle Wars entrance.

Travelling west from Yanille or Gu'Tanoth.

The Balloon transport system has an end point just north-east of the entrance.

Fairy ring code BKP teleports players south of the building.

Use the Mobilising Armies teleport and keep walking north.

Use the Spirit tree to teleport to Tree Gnome Village and walk south-west.

By walking south-west from Ardougne.

Castle Wars has no set skill requirement, however having strong combat skills is highly suggested as Castle Wars is a primarily combat minigame. All three sides of the combat triangle are often used, with rangers and magers tending to guard and defend the base. At the same time, the meleers attack the enemy base.