Spoilers #1: Items Eligible for Upgrade

Without Heart of Winter, only four items can be upgraded:

• Girdle of Gond
• Stoutward
• Winter Wolf Pelts
• Yeti Pelts

Three new items are available as well: Boomerang Dagger +1, Elven Chain, and Returning Dart +2

With Heart of Winter, more items are available for upgrade:

• Bren Muller's Crossbow
• Cynicism
• Mystery of the Dead
• The Sword of Myrloch Vale
• Young Rage

Two monsters drop items which can be upgraded, similar to rhino beetles and umber hulks.

Three more new items are available as well: Bag of Plenty +1, Case of Plenty +1, and Quiver of Plenty +1.