Games like Portalborn
Games like Portalborn include Grim Dawn, Path of Exile 2, Wolcen: Lords of Mayhem, Chronicon, and Torchlight II. We matched them by the tags players give Portalborn on Steam (Text-Based, Dungeon Crawler, RPG, Procedural Generation, and Loot): closest matches first, and among equally close ones the better-known games.

Grim Dawn
Shared: RPG · Loot · Dungeon Crawler

Path of Exile 2
Shared: RPG · Loot · Dungeon Crawler

Wolcen: Lords of Mayhem
Shared: RPG · Loot · Singleplayer

Chronicon
Shared: Dungeon Crawler · Loot · RPG

Torchlight II
Shared: RPG · Dungeon Crawler · Loot

Last Epoch
Shared: RPG · Loot · Dungeon Crawler

Path of Exile
Shared: Dungeon Crawler · Loot · RPG

Minecraft Dungeons
Shared: Dungeon Crawler · RPG · Adventure

Wayfinder
Shared: Dungeon Crawler · Loot · RPG

Torchlight
Shared: RPG · Dungeon Crawler · Loot

Torchlight: Infinite
Shared: RPG · Loot · Dungeon Crawler

Diablo® IV
Shared: RPG · Loot · Dungeon Crawler

Fallout: New Vegas
Shared: RPG · Singleplayer · Exploration

Portal Knights
Shared: RPG · Adventure · Crafting

鬼谷八荒 Tale of Immortal
Shared: RPG · Singleplayer · Adventure

Exanima
Shared: Dungeon Crawler · RPG · Adventure

Fallout 4
Shared: RPG · Singleplayer · Adventure

Crimson Desert Enhanced
Shared: Singleplayer · RPG · Adventure

Torchlight III
Shared: RPG · Dungeon Crawler · Loot

Black Myth: Wukong
Shared: RPG · Singleplayer · Action

The Slormancer
Shared: Dungeon Crawler · Loot · RPG

UnderMine
Shared: Dungeon Crawler · RPG · Procedural Generation

The Incredible Adventures of Van Helsing
Shared: RPG · Loot · Adventure

The Elder Scrolls IV: Oblivion® Game of the Year Edition (2009)
Shared: RPG · Singleplayer · Adventure