Games like Grim Siege
Games like Grim Siege include Magic: The Gathering Arena, Monster Train, Shadowverse: Worlds Beyond, Slay the Spire 2, and The Bazaar. We matched them by the tags players give Grim Siege on Steam (Card Battler, Strategy, Trading Card Game, Turn-Based Tactics, and PvE): closest matches first, and among equally close ones the better-known games.

Magic: The Gathering Arena
Shared: Strategy · Trading Card Game · Card Game

Monster Train
Shared: Card Battler · Turn-Based Tactics · Card Game

Shadowverse: Worlds Beyond
Shared: Card Battler · Trading Card Game · PvP

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

The Bazaar
Shared: Strategy · Card Battler · PvP

GWENT: The Witcher Card Game
Shared: Strategy · Card Game · Trading Card Game

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

Marvels Midnight Suns Digital Edition
Shared: Turn-Based Tactics · Turn-Based Strategy · Deckbuilding

Inscryption
Shared: Card Battler · Card Game · Strategy

Library Of Ruina
Shared: Strategy · Card Game · Deckbuilding

Animation Throwdown: The Quest for Cards
Shared: Card Battler · Trading Card Game · Strategy

9 Kings
Shared: Strategy · Card Game · Card Battler

Gordian Quest
Shared: Card Battler · Strategy · Card Game

Chrono CCG
Shared: Card Battler · Trading Card Game · Card Game

Monster Train 2
Shared: Strategy · Card Game · Turn-Based Tactics

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

Yu-Gi-Oh! Legacy of the Duelist
Shared: Card Battler · Card Game · Trading Card Game

Balatro
Shared: Strategy · Card Game · Deckbuilding

Wildfrost
Shared: Card Battler · Turn-Based Tactics · Card Game

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

LONESTAR
Shared: Strategy · Card Battler · Turn-Based Tactics

As We Descend
Shared: Card Battler · Turn-Based Tactics · Card Game

Roguebook
Shared: Strategy · Card Game · Deckbuilding

STAR WARS Zero Company™
Shared: Turn-Based Tactics · Strategy · Turn-Based Strategy