The secret cow level in Diablo 4 is as it reads, a hidden room or area that contains cows instead of enemies. Think of it as a bonus round because killing these cows should drop a ton of loot and rewards.
For players new to the franchise, a secret cow level was added to the first Diablo game as an easter egg back in 1996. If you managed to find the level, you would have to fight against an army of giant weapons-wielding cows.
Diablo 2 made it less of a secret and more of a feature. You could enter the cow level through a crafting recipe by using the Horadric Cube.
Diablo 3, in contrast, decided against adding any such level. All it had was a reference to the long-running easter egg.
With Diablo 4 out, it reasons that players are wondering if Blizzard Entertainment has indeed hidden a secret cow level. The developer (and publisher) has categorically denied adding any such hidden level. However, internet sleuths believe otherwise.
How to unlock the secret cow level in Diablo 4
To reiterate, Blizzard Entertainment has categorically denied adding any secret cow level in Diablo 4. However, players and fans alike have been bashing their heads together nonetheless to discover the hidden cow realm.
Interestingly, their pursuit of unraveling the cow mystery has uncovered certain clues of sorts that may hint at the existence of a cow level.
Do note that their discoveries do not confirm any such cow level in Diablo 4, but they do make for an interesting fan theory.
Diablo 4 clues that hint at a secret cow level
A landmark in Sanctuary, a few quest items, a key, and a quest itself were discovered through data mining during the beta releases of Diablo 4.
The working theory, at least for the time, was that you had to combine and use the items somehow to create a portal to the secret cow level.
Clue #1 – The Oxen Gods’ fountain
Head to Ked Bardu and then make your way to the eastern part of the town as shown on the map below. You are going to come across a strange fountain with four cows on each corner.
Interacting with any of these cow idols gives you a message that you can use the fountain to cleanse offerings to the “Oxen Gods” in Diablo 4. That is how you “gain their blessing”.
Clue #2 – The three Quest Items
Thanks to data-mining, we know that Diablo 4 originally had three quest items: Bloody Wooden Shard, Musty Tome, and Intricate Metallica Fragment.
The first two items can be considered strong references to items that were used to access the secret cow level in Diablo 2: Wirt’s Leg and a Tome of Town Portal.
The Musty Tome looks just like the Tome of Town Portal from Diablo 2, and the item description of the Blood Wooden Shard teases the letter “W” carved on the side—Wirt’s Leg. Continuing with the same line of thought, the Intricate Metallica Fragment may as well be a broken piece of the Horadric Cube.
Once again, these three items were unavailable in the main, live version of Diablo 4. They were only found as unused files or remnants of some old code.
Clue #3 – The mysterious key
Diablo 4 data miners were also able to discover a “Strange Key” with a rather C-shaped key ring. This was also never released in the live version of the game, but its item description did tease that it gives off “some kind of power”.
What do the clues say?
It was suggested that you would first find the three quest items and bring them to the Oxen Gods’ fountain. Cleansing them in its waters would give you a key to unlock a secret cellar. That or give you access to another hidden room.
Either way, using the key would give you access to the secret cow level in Diablo 4. Unfortunately, this theory was put to rest with the release of patch 1.0.3 which removed code for an unreleased side quest that involved the Oxen Gods.