Diep.io Wiki
Diep.io Wiki

This mysterious fortress has stood for centuries, its inhabitants having terrorizing the nearby land for about as long as they remember. While they have nearly no ties with the polygons, they agree on the destruction of the tanks and thus must be stopped. Tear that fort down before they do the same to us!

Iron Fort is a gamemode. Created by Fall Out Wave.


Like Tower of Gladii, Iron Fort has a pre-planned map and can only be beaten in a certain way.

The fort has 5 floors and a basement. All players start at level 45, and will have to slowly work their way up to the fifth to do battle with the League of Iron. If players die, they respawn at the very start, though still at level 45. Once the fort is beaten, it stays closed for the rest of the day.

Map design

The first floor.

The first floor of the map is a large rectangle divided into multiple areas. First, south of the fort is the spawn area, connected to the fort by a bridge. Once you enter the fort, there is a large rectangular room with 3 gates, one of which is locked. To get the corresponding key for each gate, one must kill enough enemies for it to drop out of a key dropper. The gates are colour-coded on each floor. Enemies, which are metallic AI versions of level 45 tanks, spawn from enemy spawners every 10 seconds. They have randomized builds and classes. At the end of the room is a teleporter that brings you to another floor. Once you go up, there is no turning back (usually anyway.)

The second floor.

The second floor is, again, a large rectangle shaped room with a large, randomly generated labyrinth that takes up most of the room. While the walls are completely random, 4 things do not change. The first is the start zone, which is where you end up after entering the first floor's teleporter. The second and third are the 2 key dropper rooms at the sides of the labyrinth. The fourth is the end room with the teleporter to the third floor. There is always a path leading to the 4 constant rooms.

The third floor.

The third floor features many, MANY lava pools that mean instant death if anything touches them, even enemies. In the middle of these pools are thin bridges that are safe to tread upon. Enemies spawn from the corners, and there are 3 key droppers. 2 of them are near the spawn zone and unlock gates that lead to the third key dropper, which unlocks gates leading to the teleporter in the middle of the room. The locked gates block off both the routes to the upper area and the teleporter.

The fourth floor.

The fourth floor is a rather simple floor with 10 spawners, 3 gates and 2 teleporters. But why are there 3 gates when there are only 2 key droppers?

The basement.

That's because the key dropper leading to the fifth floor is in the basement! In the basement, there are a whopping 24 spawners which all contribute to the key dropper in the middle of the room. There is also a teleporter which leads back to the first floor.

The fifth floor is simple. It is a large empty room, with absolutely no decoration whatsoever.


Once the first floor is entered, enemies will start spawning. For the first floor, 50 enemies need to be killed in order for a key to drop. Once a key is dropped, the gate will open for 1 minute and all tanks must rush to the gate before it closes again. The blue gate is behind the red gate, so players are recommended to kill 50 enemies on the left side, then the right. Once they are in the final room of the first floor, they can choose to access the basement or the second floor.

The second floor's labyrinth is random each time the server opens, and the walls are exactly like those in Maze. Each key needs 100 enemy deaths to drop. The minimap on this floor is disrupted and cannot show the map; instead, it shows static. For here, the preferred strategy would be having some tanks stay at the 2 rooms and keep the gates open while others navigate the labyrinth.

The third floor requires good teamwork as the pink key unlocks the path to the purple key dropper on the turquoise key dropper's side and vice versa. The pink and turquoise keys need 100 enemy kills to drop while the purple key needs 150. Since enemies will also be blocking the bridges and can potentially push you into the lava, it is best to fight the enemies on relatively safer grounds such as the areas left and right of the spawn zone. The bottom left enemy spawners activate the pink key dropper, the bottom right activates turquoise and both top left and top right activate purple. While it is possible to knock an enemy into lava, it would require massive knockback from bullet spam. Best avoid using Destroyer classes here as the knockback might knock you into lava.

Smart players know to access the basement from the first floor, but new players will go to the fourth floor, open the brown and dark red gates, then enter the basement and realize they took the wrong path. It is advised for newer players to stay in the fourth floor while older, more experienced players go to the basement.

There's not much to do in the basement. You just kill enemies over and over again, until you reach a grand total of 500 enemy kills; THEN the tan gate will finally open, thus granting access to the fifth floor.

The fifth floor is where the big battle happens and lots of tanks die. Since each member of the League of Iron has a different battling style, large amounts of tanks are needed to combat them. More about the actual fight here: League of Iron