A Baldur's Gate 3 player has discovered what's definitely a strong candidate for the absolute worst ending in the game - but you'll only get it if you can get around the developer's safeguard.
This article contains spoilers for various Baldur's Gate 3 endings.
There are various ways that you can bring your Baldur's Gate 3 story to an end before the actual conclusion of its story. You can get your brain munched on by the Mind Flayer trapped in the wreckage of the Nautiloid, or explode Gale's magical heart nuke at the end of Act 2, or even explode Gale's magical heart nuke at the end of Act 3. However, the main narrative is bringing you to a conclusion where you choose whether to destroy or dominate the Netherbrain, for which you'll need all three of the Netherstones collected from Ketheric Thorm, Enver Gortash, and Orin the Red.
Those Netherstones are so story-critical that unlike almost any other item in the game, you can't use the 'Throw' action on them. Presumably that's to put an obstacle between the player and an abyss-bound stone, but it's not a fool proof barrier - if you place a stone in a container, you can then throw that box, chest, crate, sack or barrel into the aforementioned abyss, triggering an ending.
As spotted by PC Gamer, putting any of the three stones beyond your reach places you in a cutscene in which your Mindflayer overlooker, the Emperor, admonishes you for your stupidity. Immediately after that, the Netherbrain is able to exert its influence over you, activating the tadpole in your head and turning you into a Mindflayer yourself. At that point, as you float thoughtlessly towards your new master, a Game Over screen appears to tell you that "the only path now leads" to the brain, forcing you to reload a save.
It's pretty bleak - even more so than the cutscene that triggers at the end of the Baldur's Gate 3 speedrunning strategy that sees Gale destroy the brain a full Act before he's supposed to, during which the narrator tells you that this is "an ending, of sorts." Clearly it's not where you're supposed to end up, but it's testament to the detail that's packed into Baldur's Gate. Not many games would give you access to a story-ruining item and then let you casually lob that item away, and very few would craft an entire motion-captured ending for that eventuality. It's far and away the worst Baldur's Gate 3 ending on offer, but the fact that it's even on offer at all is pretty impressive.
To put just how bad this ending is into perspective, there are 17,000 Baldur's Gate 3 endings, and this one is still the worst of the lot.