Games like Realmbound Frontier
Games like Realmbound Frontier include Griftlands, Slay the Spire, Monster Train, 9 Kings, and Balatro. We matched them by the tags players give Realmbound Frontier on Steam (Card Battler, Strategy, RPG, Choose Your Own Adventure, and Roguelite): closest matches first, and among equally close ones the better-known games.

Griftlands
Shared: Card Battler · Roguelite · RPG

Slay the Spire
Shared: Card Battler · Card Game · Strategy

Monster Train
Shared: Card Battler · Roguelite · Card Game

9 Kings
Shared: Strategy · RPG · Card Game

Balatro
Shared: Card Game · Strategy · Roguelite

Slay the Spire 2
Shared: Strategy · Card Game · Card Battler

Journey to the West
Shared: Card Battler · RPG · Roguelite

Super Fantasy Kingdom
Shared: Strategy · RPG · Roguelite

Cross Blitz
Shared: RPG · Card Battler · Roguelite

The Last Spell
Shared: Strategy · RPG · Turn-Based Strategy

Inscryption
Shared: Card Battler · Card Game · Strategy

Roguebook
Shared: RPG · Strategy · Card Game

Stacklands
Shared: Card Battler · Card Game · Roguelite

NEOVERSE
Shared: Card Battler · Roguelite · Strategy

Overdungeon
Shared: Strategy · RPG · Card Battler

Morimens
Shared: Card Battler · Roguelite · Strategy

Mewgenics
Shared: Roguelite · RPG · Turn-Based Strategy

Dungeons & Degenerate Gamblers
Shared: Strategy · Card Battler · Card Game

Gordian Quest
Shared: Card Battler · RPG · Strategy

Dream of Corpse Lady
Shared: Strategy · Card Battler · Card Game

Across the Obelisk
Shared: Casual · Card Battler · Turn-Based Strategy

Warhammer 40,000: Rogue Trader
Shared: RPG · Strategy · Turn-Based Strategy

Thea 2: The Shattering
Shared: Strategy · RPG · Card Battler

Die in the Dungeon
Shared: Strategy · Card Battler · Card Game