AKITSORA GAMING

Thread-Bound

Stitch by stitch, loose signatures become a book — a Japanese bookbinding studio in the afternoon light.

Thread-Bound is a 6×5 tumbling slot set in a Japanese stab-binding studio. 8+ matching symbols pay anywhere; new-print signatures trigger free spins with accumulating gold bookmark multipliers.

Demo play uses virtual credits with no monetary value.

RTP
96.70%
Volatility
High11.20
Max win
5,000× bet
Bonus buy
100× bet

In-game screens

Captured straight from the running game — real boards, real wins.

Thread-Bound — Base game
Base gameA 6 × 5 board. Matching symbols pay anywhere on it.
Thread-Bound — Cascading win
Cascading winWinning symbols fold away like paper into a signature, a red thread stitches through them, new ones drop in, and a single spin can pay several times.
Thread-Bound — Free spins
Free spinsIn the finished-book showroom the collected multiplier accumulates for the whole feature and applies to every later win.
Thread-Bound — Big win
Big winA single round is capped at 5,000× the bet.
Thread-Bound — Bonus buy
Bonus buyBuy straight into free spins for 100× the bet. Buy RTP is measured separately.
Thread-Bound — In-game paytable
In-game paytableThe same game definition as the table on this page: the game receives it from the server, and this page reads it at build time.

Specification

Type6 × 5 tumble, scatter pays (no paylines)
Return to player (RTP)96.70%
Bonus buy RTP96.41%
VolatilityHigh (11.20)
Hit rate48.97%
Max win per round5,000× bet
Free spins frequency≈ 1 in 214.68 spins
Calibration sample2,240,000,000 spins, standard error 0.02%

Game math specifications and the paytable are read at build time from the definitions shared with the server code. See Math version for the configuration shown; confirm any other version or operator-specific settings separately.

How wins work

  • A 6 × 5 board. 8 or more matching symbols anywhere on it pay — no paylines, no adjacency requirement.
  • Winning symbols clear and new ones drop in from above, so a single spin can chain several wins.
  • Each win = (bet ÷ 20) × symbol multiplier × active multiplier.
  • As a rule, at most 2 of the same symbol appear per column, which prevents full-column stacking and keeps clusters spread across the board.

Paytable

Values are the symbol multiplier in: win = (bet ÷ 20) × symbol multiplier × active multiplier.

Symbol8–910–1112+
Binding needleHigh-pay 2005001000
Thread spoolHigh-pay 50200500
Bone folderHigh-pay 40100300
Thread-bound bookHigh-pay 3040240
Paste dishLow-pay 2030200
Paper corner guardLow-pay 1624160
Bamboo scraperLow-pay 1020100
Folded margin stripLow-pay 81880
Round pincushionLow-pay 51540

Special symbols

New-print signatures (scatter)

No lines, no adjacency — 4 anywhere on the board trigger the free spins feature.

Gold bookmark

Counts when a win lands. Base game ×2–×20, free spins ×2–×500.

Features

Gold bookmarks (multipliers)

Counted only when a win lands; the number on the bookmark is the multiplier. Base game ×2 – ×20. Bookmarks on the board when a win lands are summed and applied to that cascade's win; they do not carry across cascades.

Free spins

4 new-print signatures award 15 spins in the finished-book showroom. Bookmarks in free spins run ×2 – ×500, and the collected multiplier accumulates for the whole feature, applying to the current and every subsequent win.

Retrigger

3 more signatures during free spins add 5 spins, with the accumulated multiplier carried over.

Bonus buy

Buy directly into free spins for 100× the bet. Bonus buy RTP (96.41%) is measured separately from the base game.

Dry-spin rescue

After 15 consecutive rounds paying less than 1× the bet, the next spin is topped up to a cluster of 8 low-pay symbols — and so is every spin after it until a round pays at least the bet. Only completed rounds still queryable in the live system count; earlier progress may no longer be retained after a long absence. The rescued spin's bet may not exceed the lowest bet of those 15 rounds; at a higher bet that spin is not topped up. Base game only; bonus buys do not count. The RTP in the spec table assumes continuous play of this game at one bet size and includes this feature's contribution (about 2.66 percentage points).

Technical

Game codeaki_threadboundbooks
Math versionv96
TechnologyHTML5, no plug-in; one client for desktop and mobile
ViewportLandscape with proportional scaling
In-game languageTraditional Chinese (additional languages on request)
CurrenciesTWD (others can be registered on request)
IntegrationTransfer wallet (Operator API v3), launch-token redirect

Sources & verification scope

This product specification is written and maintained by its developer, Akitsora Gaming (AKI電子 in Taiwan). Measurement methods and sample information for RTP, volatility and hit rate appear in the specification table. Sampled results have uncertainty; RTP describes long-run return, not an individual player or session outcome.

Internal simulations and tests are not independent certification. We do not currently hold GLI or BMM certification reports. Supply to a market requiring third-party certification depends on completing its requirements.

See slot game development and supply for integration and supply scope, About us for development and content responsibility, or contact us for a math summary, version confirmation or a correction to this page.

The story

Fiction and adapted settings written by Akitsora Gaming for this title, including invented dialogue and events. This is not a historical or folklore reference. The rules and specification tables define the gameplay and math.

A book is not finished when it is printed — it is finished when the loose pages are sewn together, stitch by stitch.

I. Signatures

Each printed sheet is folded in half, and the fold must be crisp. A bone folder is drawn along the crease until the paper fibres lie flat. The folded sheets stacked together make a signature.

The signatures are laid out in order, their edges offset a little, like a fan just opening.

II. Four-hole binding

A Japanese book is bound on the right. An awl pierces four holes beside the spine, and a needle carrying red thread passes out through a hole, around the spine, and into the next.

The moment the thread pulls tight is the weight of the spin — the number on the gold bookmark (base game ×2 to ×20).

III. The finished-book showroom

Gather 4 new-print signatures and the cover swings open onto the showroom, red-bound books lined up on the shelves. Over the next 15 spins the multiplier keeps growing (×2 to ×500).

3 more signatures add 5 more spins.

IV. One volume

The last stitch is knotted, the thread is cut, and the title slip goes on the cover. The loose pages are a book now.

Want to spin Thread-Bound yourself?

The demo needs no account — click and spin. For integration docs, the math summary or sandbox access, send us an email.

Demo play uses virtual credits with no monetary value.