# How co-op works (at a high level)
In a cooperative run, multiple players climb the same Spire together, each piloting their own character and deck while sharing the run's timeline. You take fights as a team, and the team only progresses when the encounter is cleared. That single fact drives almost everything: because a fight ends when the group succeeds, your job is not just to play your deck well, but to make the whole team's turn add up to a win.
Your deck is yours
You still draft, thin, and pilot a personal deck. Individual deckbuilding skill matters as much as ever.
The run is shared
Path commitments, the boss in front of you, and the fight clock are common to the whole group.
Coordination wins
Two coherent decks aimed at the same fight beat four players soloing in parallel.
# Early Access caveat
# Role & archetype split
The biggest free win in co-op is not having everyone build the same deck. Split the team across complementary jobs so the group covers more fight profiles than any solo deck could.
Frontline / burst
Bias toward early removal and immediate damage. Your job is to delete threats fast — especially scaling and summoning enemies — so the builders survive the ramp-up turns.
Scaler / builder
Build the engine that wins the boss. You may be weaker in Act 1, so let the frontline carry early fights while you assemble.
Support / control
Lean into debuffs (Weak, Vulnerable) and team utility so every teammate's damage and survival improves at once.
Flex / closer
A deck that can pivot to whatever the team is missing, and that holds a finisher or panic button for clutch turns.
The roster spreads naturally across these jobs: an aggressive Ironclad or Shiv-Silent leans frontline, an orb Defect or Star Regent leans scaler, and a debuff-heavy build slots into support. See the build hubs to pick an archetype per character.
# Communication beats perfect math
The most common co-op loss isn't a weak deck — it's two players assuming the other will handle a threat, and nobody does. A few habits prevent almost all of it:
- Call the path before committing — agree where you're heading and why (rest, shop, elite).
- Announce potion use so nobody double-spends on the same emergency.
- Assign targets out loud: 'I've got the buffer, you cover the big attacker.'
- Say when you're low or out of answers so a teammate can pick up the slack.
- Flag your win condition early so the team can draft around supporting it.
# Splitting threats
In multi-enemy fights, divide the board instead of everyone piling on the same target. The priority order is the same as solo play — buffers and summoners first — but now you can assign it:
Burst takes the snowball
The frontline deletes the enemy that scales or summons before it spirals out of control.
Support softens the rest
Apply Weak to the big attacker and Vulnerable to whatever the team is about to focus.
Don't overkill
Coordinate so two players don't both dump lethal into the same low-HP enemy and waste a turn of damage.
# Shared resources & pacing
Whatever the exact sharing rules turn out to be, the principle is the same as solo play scaled up: don't hoard, and spend resources where they buy the most for the team. Coordinate rests, big purchases, and consumables instead of each player optimising in isolation.
Plan as a group
- Decide who takes the rest-site upgrade vs. heal.
- Funnel a key relic or remove to whoever it helps most.
- Stage potions so the team has answers at the boss.
Pace the build curve
- Let the scaler skip risky early fights they don't carry.
- Have the frontline absorb early elites if the team agrees.
- Aim for everyone's win condition to be online by the boss.
# Common pitfalls
- Four identical aggressive decks with nobody scaling for the boss.
- Silence: assuming a teammate will cover a threat that then goes unblocked.
- Hoarding potions and finishers across the whole party until someone dies holding them.
- Tunneling on your own deck while the team's overall turn falls apart.
- Pathing disagreements mid-act — settle the route before you commit, not after.
Build your half of the team
Pick a character archetype that fills a role your squad needs.