Tool

Draw-odds calculator: will you find the card?

Compare deck size, useful copies and draw count without an account.

Early Access · Main 0.107.1 baseline; Beta 0.111.0 changes marked · Updated 2026-09-12

The short answer

Enter the remaining random draw pile, the copies that solve your problem and how many cards you will draw. The calculator returns the chance of seeing at least one useful copy.

Compare your next draw

44.7% chance of drawing at least one useful copy.

Uniform random draws from one pile, without replacement or a reshuffle. Known card order and game effects are excluded. Runs locally; no account or uploaded deck.

Before you start

  • Count only the cards that can be drawn from the pile being modelled.
  • This is a probability model, not a simulation of a seeded run.

Use the current pile, not automatically the full deck

Exclude cards already in hand, exhausted cards and anything outside the draw pile. If a reshuffle occurs during the draw sequence, split the situation into separate stages; this calculator assumes one finite pile with no replacement.

Kingy example: among 20 cards, two are useful and five will be drawn. The chance to find at least one is about 44.7%. At the same copy count and draw count, reducing the pile to 15 raises it to about 57.1%. Neither percentage measures the quality of the rest of the deck.

Sources for this section

What the result includes

The model computes one minus the probability of drawing only non-target cards: 1 − C(N−K, d) / C(N, d). N is pile size, K is useful copies and d is draws. It assumes every ordering is equally likely.

Known top cards, Innate, Retain, generated cards, forced draw, discards, reshuffles and the game’s deterministic seed can change the real outcome. Use the result to compare simple draft or removal scenarios, then return to the actual hand and enemy intent.

Sources for this section

Your checklist

0 of 3 ready · Stored only while this page is open.

Research checked 2026-09-12. This is a source-based guide; Kingy has not independently play-tested these steps. Evidence and coverage.

Independent fan guide. Slay the Spire 2 belongs to Mega Crit. Illustration by Kingy; not game footage.