Free Spins
Land 3–5 scatters for 8 / 12 / 15 free spins. 2+ scatters during free spins retrigger +2 more. Free-game reels run hotter wilds with gold expanding wilds. H5 green frog pays in free game only.
Featured Software · 2026
Lost Island
A production jungle adventure casino slot — full math engine, Svelte/PixiJS client, free spins, coin Hold & Spin, expanding wilds, and jackpot tiers — built under contract for platform distribution.
96%Target RTP (MC validated)
12Fixed paylines · 5×4 board
25,000×Max win envelope (design)
4Jackpot tiers · coin respin
Project Overview
What We Built
Lost Island is a production-grade 5×4, 12-line casino slot built under contract with Rush Social Game Studios for Stake Engine distribution. Scott Applications delivered the full game stack: a certified 96% RTP math model (Python/Stake Engine SDK with free-game and coin Hold & Spin features), a high-performance Svelte + PixiJS web client with polished desktop landscape and mobile portrait HUDs, tiki jackpot pillars, expanding wilds, free spins (8/12/15) with retriggers, coin respins with MINI/MINOR/MAJOR/GRAND jackpot tiers, max-win celebration, and operator-ready compliance polish. Shipped as a complete frontend + math package — from loading screen art, in-game info pages, and symbol set through live spin UI.
iGamingSveltePixiJSPython MathStake EngineTypeScript
Visuals
Live Previews & Production Art
Desktop landscape, mobile portrait, max-win celebration, feature banners, jackpot board, reels frame, and symbol art from the shipping client.
Math Engine
RTP, Volatility & Feature Economics
Math was treated as a hard constraint — not a post-art guess. Monte-Carlo simulation (≥5M spins) seeded the production optimizer for Stake Engine 2-Star envelopes.
Certification Snapshot
| Metric | Target | Validated | Status |
|---|---|---|---|
| Total RTP | 96.0% | 95.83% MC mean (±0.41%) | Pass |
| Base-game volatility | 2-Star envelope | ~2.0 std dev | Pass |
| Max win / wincap | ≤ 25,000× | 25,000× design cap (2-Star) | Pass |
| Paylines | 12 fixed | 5×4 board · L→R lines (was 40) | Pass |
| RTP split | — | Base ~74% · Free ~9% · Coin ~13% | — |
| Free-spin trigger | — | ~1 in 466 | — |
| Coin respin trigger | — | ~1 in 366 (≥6 coins) | — |
Board & Rules
- Board: 5 reels × 4 rows · 12 fixed paylines (updated from 40)
- Bet unit: 40 credits = 1× total bet (engine anchor after 12-line port)
- Wild multipliers on a winning line are SUMMED (not multiplied)
- Free spins: 3/4/5 scatters → 8 / 12 / 15 spins · 2+ scatters retrigger +2
- Coin Hold & Spin: 3 respins, reset on each new coin (≥6 coins)
- Jackpot tiers (× bet): MINI 20× · MINOR 100× · MAJOR 500× · GRAND 5,000×
Game Features
What Players Feel
Three feature pillars — free spins, coin respins, and expanding wilds — each wired through math modes and the live client.
Coin Hold & Spin
Six or more coins on a base spin starts Hold & Spin: 3 respins that reset every time a new coin lands. Coins lock cash values or MINI / MINOR / MAJOR / GRAND jackpot tiers.
Expanding Wilds
Standard wilds and gold expanding wilds (WG) participate in line wins. Wild multipliers in a winning run are summed — a design detail that shapes both feel and RTP tuning.
Interactive Game Info
Paytable · Lines · Bonus Buy
Live-style controls for the shipping 5 reels × 4 rows · 12 fixed paylines model — production math from the shipping game_config (12 lines, 40-credit bet unit). Change total bet to see cash pays and all five bonus-buy costs scale live.
Total Bet12 lines · 40 credits = 1×
$1.00
MINI$20.0020× bet
MINOR$100.00100× bet
MAJOR$500.00500× bet
GRAND$5,000.005000× bet
Paying Symbols
H7
Explorer
Top premium pay symbol
- 5×40× bet$40.00
- 4×16× bet$16.00
- 3×6.5× bet$6.50
H6
Tourist Man
Premium character
- 5×25× bet$25.00
- 4×10× bet$10.00
- 3×5× bet$5.00
H1
Crocodile
High-pay animal
- 5×15× bet$15.00
- 4×6× bet$6.00
- 3×3× bet$3.00
H4
Orange Frog
High-pay frog
- 5×12× bet$12.00
- 4×5× bet$5.00
- 3×2.5× bet$2.50
H5
Green Frog
Premium — free game only
Free game only- 5×10× bet$10.00
- 4×4× bet$4.00
- 3×2× bet$2.00
H2
Tarantula
High-pay arachnid
- 5×6× bet$6.00
- 4×3× bet$3.00
- 3×1.5× bet$1.50
H3
Spider
High-pay spider
- 5×5× bet$5.00
- 4×2.5× bet$2.50
- 3×1× bet$1.00
L1
Ace (A)
Low royal
- 5×1× bet$1.00
- 4×0.5× bet$0.50
- 3×0.1× bet$0.10
L2
King (K)
Low royal
- 5×1× bet$1.00
- 4×0.5× bet$0.50
- 3×0.1× bet$0.10
L3
Queen (Q)
Low royal
- 5×1× bet$1.00
- 4×0.5× bet$0.50
- 3×0.1× bet$0.10
L4
Jack (J)
Low royal
- 5×1× bet$1.00
- 4×0.5× bet$0.50
- 3×0.1× bet$0.10
L5
Rope
Low object (same ladder as royals)
- 5×1× bet$1.00
- 4×0.5× bet$0.50
- 3×0.1× bet$0.10
Specials
W
Wild
Substitutes · mult 1–100× (1× green / 2+ purple) · line pays match H1
Substitutes for all paying symbols. Mult 1–100× (1× green / 2+ purple art). Multipliers on a winning line are summed.
- 5×15× bet$15.00
- 4×6× bet$6.00
- 3×3× bet$3.00
WG
Gold Expanding Wild
Expanding wild · mult 1–15× · expands up/down column on land
Gold lady expanding wild · mult 1–15×. On land, expands up & down the column. Line pays match H1 / W.
- 5×15× bet$15.00
- 4×6× bet$6.00
- 3×3× bet$3.00
S
Scatter (Volcano)
3 / 4 / 5 → 8 / 12 / 15 free spins · 2+ in free game retrigger +2
3 / 4 / 5 scatters → 8 / 12 / 15 free spins. During free spins, 2+ scatters retrigger +2 spins.
C
Coin
≥6 coins trigger Hold & Spin · cash values or jackpot tiers
Land 6+coins to start Hold & Spin: 3 respins, reset on each new coin. Coins lock cash or jackpot tiers.
Symbol Set
Every Symbol, Individually
Production art for each paying symbol and special — cropped from the shipping symbol sheet and mapped to math codes used in paytables, strip generation, and client rendering.
Explorer
Top premium · 40× / 16× / 6.5× bet
Tourist Man
Premium · 25× / 10× / 5× bet
Crocodile
High · 15× / 6× / 3× bet
Orange Frog
High · 12× / 5× / 2.5× bet
Green Frog
Free game only · 10× / 4× / 2×
Tarantula
High · 6× / 3× / 1.5× bet
Spider
High · 5× / 2.5× / 1× bet
Ace (A)
Low · 1× / 0.5× / 0.1× bet
King (K)
Low · 1× / 0.5× / 0.1× bet
Queen (Q)
Low · 1× / 0.5× / 0.1× bet
Jack (J)
Low · 1× / 0.5× / 0.1× bet
Rope
Low object · same ladder as royals
Wild
Mult 1–100× · pays as H1
Gold Expanding Wild
Mult 1–15× · expands column
Scatter (Volcano)
3/4/5 → 8/12/15 free spins
Coin
Hold & Spin · cash / jackpot tiers
Delivery Stack
Frontend, math, and platform contracts owned as one system so spin books and UI state stay aligned from simulator to live play.
SveltePixiJSTypeScriptPythonStake Engine SDKMonte-Carlo SimMobile HUDBonus Buy
Contracted Studio Partner
Rush Social Game Studios
Lost Island was engineered under contract with Rush Social Game Studios — studio IP and art direction paired with Scott Applications' math, client, and compliance engineering for Stake Engine distribution.
Our Stack
Technologies Behind Lost Island
Math, client, and platform tooling treated as one shipping system — not three disconnected freelancers.
Game Client
Svelte + PixiJS
TypeScript
Mobile HUD
Bonus Buy / Features
Math & Platform
Python Math SDK
Monte-Carlo Sim
Stake Engine
2-Star Envelope
Delivery
Git Workflows
Tooling / RGS
iGaming Features
Full-Stack Ownership
Free Evaluations
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