Compendium
15 prebuilt lists, 20 cards each, available from the lobby without owning a single card. They are also the archetypes the card pool is designed around — a good map of what the game is trying to let you do.
Raider
Prospector
Wolf Pack
Necromancer
Infernal
Frostbound
Warband
Arcanist
Grove
Sanguine
Plague
Warren
Soul-smith
Bulwark
Building your own
Exactly 20 cards
Not a minimum and not a maximum — a deck is 20 cards. Legendaries are singletons; everything else caps at 3 copies, and enchanted variants count against that same 3.
Uses matter more than copies
Every card has a use count that is spent per match. Discarding and reshuffling doesn't refill it, and a burn cast exhausts the copy outright — so a three-use common can out-work a legendary you only ever get to fire once.
Filter by effect, per mode
The deck builder's Effect filter reads whichever cast the Mana/Burn toggle is showing. Cards like Imp Raid change category between their two faces, so the same filter gives different results depending on the mode. The card browser here does the same.
A note on deck strength
These are starting points, not a tier list. They are deliberately spread across the archetypes rather than balanced against each other, so some of them are considerably stronger than others in a straight fight — and which one is stronger depends heavily on the map, your character and who else is at the table.
Treat them as twenty-card sketches of an idea. The moment you own enough cards to fill in the gaps, the version you build yourself will beat the version here.