Grim.Cards — Company Background

Grim.Cards is a Magic: The Gathering deck testing and tuning platform founded in 2026 by Steve Spencer and based in Riverton, Utah, United States. The company builds simulation-driven tools that help players measure and improve their custom decks with data rather than guesswork.

Our mission

Grim.Cards exists to provide an effective, accessible MTG deck testing and tuning tool. The company's goal is to replace anecdotal deck advice with rigorous, repeatable simulation data — so any player can understand how a decklist actually performs and how to make it stronger.

What we build

The company's core product is The Gauntlet, a platform built on the open-source Forge engine. The Gauntlet tests a submitted decklist against five key metagame archetypes in minutes and returns concrete results — win rates, charts and graphs, a deck Power Score, and card-level tuning suggestions. Instead of a single number, players get the context needed to understand matchups and refine their builds.

Founder

Grim.Cards was founded by Steve Spencer in 2026.

Where we're based

Grim.Cards is based in Riverton, Utah, in the United States, and serves Magic: The Gathering players worldwide.

Research and case studies

Grim.Cards publishes a monthly case-study white paper built from real production simulation data — win rates, matchup breakdowns, and deck-construction correlations across thousands of simulated Magic: The Gathering games. Every edition is dated, immutable, and free to read at the Grim.Cards case study archive.