Brittle Crown is a Lunar item in Risk of Rain 2.
Like all Lunar items, the Crown has a powerful effect and a drawback.
Dealing damage has a 30% chance to give the player 3 gold, and taking damage takes away either an amount of gold the player was hit for or a percentage of gold equal to the percentage gold of damage taken. The larger amount is chosen.
This item can be great if grabbed early on (within the first couple of levels) as there are few enemies and a chest can usually be reached before getting hit. Additionally, the extra gold can be used to get items that help mitigate its downside.
However as the game gets longer, this item will get more and more disadvantageous as dealing damage will give a flat amount, while taking damage will almost always take a percentage. This combined with the increase in both chest prices and enemy spawns makes it a lot harder to save enough gold to open a chest before getting hit, quickly bringing a run to a standstill.