This infinite mana and damage bug ruined ranked

Mar 27, 2023

Reading time: 2 min

This infinite mana and damage bug ruined League of Legends’ ranked, and it comes from the most unlikely of places, the Undo button in the shop.

A recent bug in League of Legends was responsible for players getting effectively infinite mana and damage, and it was ruining ranked games. Rather than some other bugs, which require very specific champions to occur, this could be pulled off by any champion in any game. It wasn’t any of the usual culprits for a bug. This time it was the Undo button in the item shop.

Infinite mana and damage bug takes over ranked

Here’s how the bug worked, and it’s surprisingly simple, but it’s still in the game. The bug was very simple. If a champion had Biscuits of Everlasting Will in their inventory, they could repeatedly sell the item and undo the sale. Due to an unintended interaction, undoing the sale of the biscuit would increase their maximum mana. These are only available through the Biscuit Delivery rune in the Inspiration tree. The Biscuits are only supposed to give bonus mana when consumed, but something in the code was treating selling the item as though the champion has used it. This was used in combination with Muramana, which gives attack damage based on a percentage of total mana for effectively infinite damage.

13.6 Patch Notes:

"Fixed a bug that sometimes caused the Undo function in shop to lower total mana if biscuits were in the player's inventory."

Meanwhile in Patch 13.6…

ffs pic.twitter.com/pExmEs5TQh
— Vandiril (@Vandiril) March 23, 2023

The bug was supposed to have been fixed in Patch 13.6, and the patch notes said that the issue had been fixed. However, as fans and content creators quickly noticed, it hadn’t been fixed at all. As a result, the Biscuit Delivery rune has been temporarily disabled until the League of Legends developer can fix it. Until then, you won’t be able to get everybody’s favorite snack for the laning phase. It’s not clear what makes it so hard to fix, but the rune will remain disabled until a solution is found.