A free Commander/EDH deck builder that recommends cards by mechanical synergy and obscurity — not popularity. Every pick comes with a plain-English reason.
1
Build
Start a deck from a commander, or explore what’s out there. The engine suggests cards as you go.
two lanes — what you tap out to advance vs. interaction you hold up
Color sources
Frank-Karsten weighted sources, not a naive pie chart
Synergy graph
force-directed map — clusters emerge as your engines
03
FAQ
What is Affinity?
Affinity is a free Commander (EDH) deck builder that recommends cards by mechanical synergy and obscurity instead of popularity — so you build a deck that plays like yours, not a net-deck.
How does the recommendation engine work?
A deterministic scoring engine rates every card on synergy, role coverage, mana curve, color sources and novelty, then explains each pick in plain terms. There is no AI guessing — the same deck always scores the same way.
Is it just EDHREC with extra steps?
No. EDHREC ranks by how often a card is played; Affinity ranks by how well a card fits your commander’s mechanics, surfacing hidden gems a popularity list buries. A novelty dial slides from proven staples to deep cuts.
What else can it do?
Deck doctor + power/bracket assessment, a goldfish simulator, combo detection, a color-source (Frank-Karsten) check, and a force-directed synergy graph of your deck.
04
Explore
Browse Commander archetypes and the commanders that define them — each with its best cards ranked by synergy, not popularity.