Great Treasure Chest

Great Treasure Chests are rare chest variants with far better rewards than the regular Treasure Chests. They have a $1⁄1000$ chance to spawn in place of a regular treasure chest.

When generating a new area, there are specific locations that can spawn an Extra Max Health or a chest. For each of these places, there's only a $2⁄5$ chance it spawns a chest. If that roll succeeds, $1⁄10$ chest spawns instead spawn a Mimic, and only $1⁄1,000$ spawn a great chest.

As a result, the probability of getting a great treasure chest from any given possible heart spawn location is $9⁄25,000$ (0.036% or $1⁄2,777$).

There are also some guaranteed chest locations which can spawn in the Mines (see the Gallery below) which have a $1⁄2000$ chance to spawn as a Great Treasure Chest instead. Having the Curse of Greed active will cause them to have a $1⁄50$ chance.

Additionally, The End of Everything drops a Great Chest at the end and also killing Syväolento awards you with a guaranteed Great Treasure Chest.

Contents
Upon opening, it spawns items according to the following table.

Bold is the individual probability for each roll, italics is the overall probability of the final outcome relative to all other outcomes.

When the chest rolls the "roll again" options repeatedly and finally stops, the potions are selected at the end of the script when it actually spawns the entities. This is why, no matter how many times it loops on itself, it only creates up to 3 different potions each time you open it. As a result, when it repeatedly rolls the random potion options, it creates a large cluster of the same few potions rather than a more random selection.

The wands get much more complex code, so while rolling the same variation of a wand repeatedly is unlikely, it is still possible.

Tips

 * Be very careful as these chests have a high chance of pulling from the random material pool, which can rarely spawn Creepy Liquid (among many other odd or dangerous materials), potentially ending a run very shortly thereafter.
 * If you spawn a Great Treasure Chest via The End Of Everything, focus on killing the Jättimato; if they destroy the chest, it may open and break the potentially very hazardous potions contained inside.