An instance is a special area, typically a quest area, that generates a new copy of the location for each player or group that enters the area. Players cannot see other players in instanced areas unless it's a group instanced area—in which case, the group cannot see any other groups.
Instanced areas can take place in entirely new areas that cannot be accessed without the instance or in areas that are normally not instanced. Most non-quest boss instances will require the player to pay a specific sum of money or have an item in their inventory access the instance.
Examples of instanced areas
- Boss areas:
- Many quest areas:
- The lower levels of the Elemental workshop
- Dream World
- The boss section of Kruk's Dungeon and Crash Site Cavern with Kruk and Glough respectively
- Raids
- Some after-quest bosses: Glough
Boss instances
Some bosses have an instance option (sometimes called "custom session" or "custom encounter"), which may have a setup or entrance cost (coins or an item). Instances also share the requirements of the boss. The cost varies per instance and are shown below.
| Boss | Access location | Cost | Notes |
|---|---|---|---|
| Zulrah | At his shrine east of Zul-Andra | Free | Should the player die, items can be reclaimed by speaking to Priestess Zul-Gwenwynig. |
| Skotizo | Centre of the Catacombs of Kourend |  Dark totem
|
Use a dark totem on the altar found in the centre of the Catacombs of Kourend. Do not bring any items you are not willing to lose as they will be lost on death. |
| Kraken | Kraken Cove | 25,000 | At the crevice due north, select the "Private Crevice" option. Do not bring any items you are not willing to lose as they will be lost on death. |
| King Black Dragon | King Black Dragon Lair | 50,000 | Go down the ladder at the Lava Maze entrance and select the "Private Lever" option. If a player dies or disconnects while inside a KBD instance, his or her items will not be retrievable. |
| Corporeal Beast | At the private portal in Corporeal Beast lair | 200,000 | A captain rank or above in a clan chat can pay the instance cost for the clan, and any clan member can enter once the instance is open. Items drop to the ground upon death, but if everyone leaves the instance or you are kicked from the clan chat, you will not be able to return to the instance to retrieve your items. |
| Grotesque Guardians | Roof entrance outside of gargoyles in Slayer Tower |  Brittle key
|
Players need to obtain a brittle key from gargoyles only while on a Slayer task, which grants access to the Slayer Tower's rooftop. If the player dies, lost items will be placed in a magical chest near the entrance. Before players can reclaim their items, they must pay 50,000 coins, however. |
Slayer instance-like sections
Some bosses may only be slain if on a Slayer assignment, namely the Kraken, Thermonuclear smoke devil, Cerberus, and Abyssal Sire. In essence, these bosses' lairs seemingly function as if they were instances since while others can still enter and possibly crash, they're blocked off from being killed to the rest of the players who aren't on task.
Additionally, Dagannoth Kings have a Slayer lair, which is accessible on the Kings' ladder. Players who are on task may kill the kings for the duration of their task and can return upon death to retrieve items.