Tool · official Trello rates only
Choose a target Stand, choose an arrow, and enter how many arrows you plan to use. The calculator shows whether the arrow can roll that Stand, the published or card-calculated chance per arrow, the chance of at least one hit, and the expected number of arrows. It also compares the crafting cost of Lucky and Bizarre Arrows with Mysterious Arrows.
Last updated
Odds
The result updates from the options you choose. The page URL carries the Stand, arrow, and arrow count, so you can share the exact calculation.
The Stand, arrow, and count are saved in the page URL.
Before you use an arrow
An arrow replaces the Stand you currently have equipped. Store the Stand you want to keep at D'Arby at the Docks. The official card lists him as Stand Storage and says he can turn your Stand into a Stand Chip.
Chance per arrow
5.00%
For King Crimson specifically.
At least one in 10 arrows
40.1%
1 − (1 − 5.00%)^10.
Average arrows for one hit
20.0
Geometric expectation: 1 ÷ 5.00%.
How this number was obtained
The official Part 5 arrow card names King Crimson at 5%.
Crafting cost comparison
Mysterious Arrow [Part 5] is crafted with 15 Arrow Parts + 2 Steel + 1 Wood. It is not made from Mysterious Arrows, so there is no Mysterious-arrow cost conversion.
Arrow rule used
Each Part 5 Stand is equally likely, except King Crimson at 5%.
No rarity exclusions are listed. Only Part 5 Stands are in its pool.
Read the official Mysterious Arrow [Part 5] cardStep by step
The list includes every released Stand, including quest, Exclusive, and Opal Roka variants. If a Stand is outside the arrow pool, the calculator says so instead of inventing odds.
The six awakening items are the Mysterious Arrow, Lucky Arrow, Bizarre Arrow, the Part 3 and Part 5 arrows, and the Mysterious Rock. Each has its own pool and its own published information.
The result shows the chance of at least one hit across that many independent rolls, plus the average number of arrows for one hit. The URL updates so you can share the exact setup.
Lucky Arrows are crafted from three Mysterious Arrows and Bizarre Arrows from nine, so the same number of rolls can cost very different amounts of materials.
No invented numbers
The calculator uses three kinds of information, and it labels which one produced each result.
Published single-Stand rates
The Part 3 arrow card gives The World and Star Platinum 5% each; the other Part 3 Stands share the remaining 90% equally. The Part 5 card gives King Crimson 5%; the other Part 5 Stands share the remaining 95%. The Mysterious Rock says every Part 9 Stand has the same chance.
Published rarity rates
The Lucky Arrow card publishes Epic 42.5%, Legendary 34%, Mythical 22.1%, and Pinnacle 1.5%. The Bizarre Arrow card publishes Legendary 57.9%, Mythical 37.7%, and Pinnacle 4.4%. These are group rates, so the calculator does not divide them by the number of Stands in the group.
Derived from official rules
Equal-chance pools are calculated exactly from the card wording. The Lucky and Bizarre cards also imply a Mysterious Arrow Pinnacle rate of about 0.50% per roll. That derived value is used only for a Pinnacle-level cost comparison and is labelled as derived.
Formulas used
1 − (1 − p)^N, where p is the per-arrow chance as a fraction.1 ÷ p. This is the expected value of a geometric distribution, not a guarantee.(100% − 2 × 5%) ÷ 7. Part 5 share: (100% − 5%) ÷ 6. Part 9 share: 100% ÷ 9.1 − (1 − p)^3 = 0.015 and 1 − (1 − p)^9 = 0.044; both give about 0.50%.The October 24 update says arrows used before finishing the story roll from a modified pool without Super Fly, Rolling Stones, or Cinderella; the November 15 update added Lyin' Eyes. The calculator uses the full published pool, so those four Stands may be unavailable in the early-game pool.
Answers
That depends on the Stand and the arrow. The Part 3 and Part 5 arrows publish single-Stand odds, with The World, Star Platinum, and King Crimson at 5% each. The Mysterious Rock says every Part 9 Stand has the same chance. Lucky and Bizarre Arrows publish only rarity-level rates, so the calculator shows the chance to roll any Stand of that rarity, not the exact Stand.
Yes. Every published rate comes from an official Stand Out Trello card. Equal-chance pools are divided exactly as the cards describe, and the only rate not printed on a card is the roughly 0.50% Mysterious Arrow Pinnacle rate implied by the Lucky and Bizarre cards. We do not fill gaps with estimates.
The official Lucky and Bizarre Arrow cards publish rates for Epic, Legendary, Mythical, and Pinnacle, but not the chance of each individual Stand inside those groups. Dividing the rarity rate by the group size would be a guess, so the calculator labels the result as a rarity-level chance.
The Lucky Arrow card says its 1.5% Pinnacle chance matches getting at least one Pinnacle from three regular arrows. The Bizarre Arrow card says its 4.4% Pinnacle chance matches at least one from nine. Solving 1 − (1 − p)^3 = 0.015 and 1 − (1 − p)^9 = 0.044 both give about 0.50% per Mysterious Arrow. This is a derived cross-check, not a rate printed on the Mysterious Arrow card.
Yes. The official FAQ says using another arrow rerolls the Stand you have. Store the Stand you want to keep with D'Arby at the Docks first: the official card lists him as Stand Storage and says he can turn a Stand into a Stand Chip.
Official Trello cards and pages used on this page. Data checked on .