Fans of Halo, streamer Charlie “Cr1tikal” White has a challenge for you: win Halo Infinite 2 on a particular difficulty setting without dying, and he’ll give you $20,000. The problem is that the game appears to be unplayable due to that custom difficulty setting.

That level of difficulty is known as “LASO,” or Legendary All Skulls On. It is a fan-made set of conditions that not only sets the game’s difficulty to Legendary but also adds a number of modifiers determined by the game’s skulls. These could be things like increasing the health of more enemies or decreasing the amount of ammo in your clips.

It is a brutal style of gaming. Here is a Reddit thread from a few years ago where someone brags about finishing Halo 2 LASO, though he does mention that he had a lot of deaths—at least triple digits worth. The goal of Cr1tikal’s challenge is to avoid dying even once.

Cr1tikal, who described this as his Willy Wonka moment, initially offered a reward of $5,000 but has since increased it by $15,000 because he thinks the task is the most difficult one currently available in gaming.

No player has ever been able to demonstrate they’ve finished a deathless LASO run in the 18 years since the release of Halo 2, which many people are unaware of. It’s so challenging that, according to Cr1tikal, who has spent the last three weeks watching people try to steal his money, 99% of players couldn’t advance past the game’s opening level, and the majority can’t even get past the opening few rooms.

The run must be streamed live on either Twitch or YouTube, according to the rules. Halo 2 must be set to Legendary difficulty, with all 13 of the game’s skulls activated but “Envy” disabled.

That’s because one player previously claimed to have finished a LASO run without dying, but they were utilizing this skull, which swaps out Master Chief’s flashlight for the capacity to actively blend in with the environment. Which isn’t making things any harder, so turning it off seems perfectly reasonable given the goal of this challenge.