Gambling Chest

        At first glance, the Gambling Chest seems mundane, but the interior is lined with a lightless black material. Should 500 gp worth of gold or items ever be placed inside the chest, the chest closes and the character that placed the items rolls 1d100 and 1d20 to generate an item using the following table:

d100              Rarity
0-49..............Common
50-84............+1 Common
85-92............Magic Uncommon
93-96............Magic Rare
97-99............Magic Very Rare
100...............Magic Legendary

        Once the base rarity of the item is determined, the d20 roll gets factored in. If the result of the roll was higher than the character's level reduce the rarity of the item by 1 level. If the result of the roll was a 1 the item is a cursed item. Once the DM determines the exact item based on the final rarity, the chest reopens with the item sitting inside, the interior of the chest now lined with a vibrant red velvet. The character now makes a Cha Saving Throw with a DC of 10 + the number of times they have used the Gambling Chest. If they fail, they recieve the Gambler's Curse and are compelled to take risks at every opportunity until the curse is removed by something like Remove Curse or Greater Restoration. Once the curse is removed, the counter of times they used the chest is also reset when being factored into future Saving Throws.

        The Gambling Chest has 120 Hit Points and is Immune to Fire Damage. If the Gambling Chest is ever destroyed, a rift to the Abyssal Plane centered on the chest forms for 30 seconds. The remains of the chest as well as any loose objects in the immediate vicinity are sucked through the rift, and any creatures that are close enough to the rift make a DC 12 Dex Saving Throw to resist the rift's pull.

Notes: *Slightly tweaked version of concept by Reddit user vysken on r/UnearthedArcana, Container, Cursed