Games like Runisthar
Games like Runisthar include Slay the Spire 2, Slay the Spire, Balatro, 9 Kings, and Die in the Dungeon. We matched them by the tags players give Runisthar on Steam (Difficult, Turn-Based Combat, Roguelike Deckbuilder, Roguelike, and Funny): closest matches first, and among equally close ones the better-known games.

Slay the Spire 2
Shared: Roguelike · Roguelike Deckbuilder · Deckbuilding

Slay the Spire
Shared: Roguelike Deckbuilder · Roguelike · Deckbuilding

Balatro
Shared: Roguelike Deckbuilder · Roguelike · Deckbuilding

9 Kings
Shared: Roguelike · Roguelike Deckbuilder · Deckbuilding

Die in the Dungeon
Shared: Roguelike · Roguelike Deckbuilder · Turn-Based Combat

Darkest Dungeon®
Shared: Turn-Based Combat · Roguelike · Difficult

Library Of Ruina
Shared: Difficult · Turn-Based Combat · Deckbuilding

Wildfrost
Shared: Roguelike Deckbuilder · Difficult · Roguelike

The Binding of Isaac: Rebirth
Shared: Roguelike · Difficult · Indie

Breachway
Shared: Roguelike · Roguelike Deckbuilder · Turn-Based Combat

Super Fantasy Kingdom
Shared: Roguelike · Roguelike Deckbuilder · Turn-Based Combat

Dicey Dungeons
Shared: Roguelike Deckbuilder · Roguelike · Deckbuilding

Monster Train
Shared: Difficult · Roguelike · Deckbuilding

Vampire Crawlers: The Turbo Wildcard from Vampire Survivors
Shared: Roguelike · Deckbuilding · Card Battler

Decktamer
Shared: Roguelike Deckbuilder · Turn-Based Combat · Difficult

LONESTAR
Shared: Roguelike · Roguelike Deckbuilder · Turn-Based Combat

Roguebook
Shared: Deckbuilding · Indie · Singleplayer

Vault of the Void
Shared: Roguelike Deckbuilder · Deckbuilding · Indie

FTL: Faster Than Light
Shared: Roguelike · Difficult · Singleplayer

Dungeons & Degenerate Gamblers
Shared: Roguelike Deckbuilder · Roguelike · Deckbuilding

Deathless. The Hero Quest
Shared: Difficult · Roguelike Deckbuilder · Deckbuilding

Astrea: Six-Sided Oracles
Shared: Roguelike Deckbuilder · Roguelike · Turn-Based Combat

StarVaders
Shared: Roguelike Deckbuilder · Difficult · Deckbuilding

Ratropolis
Shared: Deckbuilding · 2D · Card Battler