STEM
ChanceForge
A probability lab: predict first, then flip coins, roll dice into a sample-space grid, draw marbles and play Monty Hall until the pattern shows — and see why one lucky run is not the pattern.
▶ Play it nowBuilt for sittings of about 20 minutes on the screen. That is our design budget, not a measurement.
Meet your mentor
Every Spark & Anvil app has a friendly mentor character that demonstrates, asks, and patiently scaffolds learning. On-device AI personalizes the mentor's responses to your kid's progress — never connecting to a server, never collecting data.
Mentored by Chance
#29B6F6 ChanceForge is a probability and statistics lab where you predict before you run. Flip coins, roll two dice into a sample-space grid, draw marbles with and without putting them back, build probability trees and play Monty Hall many times over. You discover why randomness has patterns, why one lucky run is not the pattern, and how sure to be of a guess.
Characters who teach
Meet the cast
Each character in ChanceForge is one idea in data and chance: counting outcomes, drawing graphs, finding the middle, sampling, probability trees, likelihood, spread, the chance it doesn't happen, how new facts change the odds, and the long-run average.
Tally the Counter-of-Outcomes
Data collection + frequency counting (the foundational "what happened, how often?" move)
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Display the Picture-Maker
Graphs and visual displays (bar charts, histograms, dot plots, line graphs — turning numbers into pictures)
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Center the Middle-Finder
Central tendency — mean, median, mode (the "what's typical?" question)
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Sample the Estimator
Sampling, sampling distributions, inference from sample to population
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Tree the Compound-Brancher
Compound events and probability trees — multiplication rule for independent events, addition for disjoint, conditional dependencies
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Odds the Likelihood-Reader
Basic probability — placing a chance on the 0-to-1 scale from impossible to certain
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Scatter the Spread-Reader
Spread and variability — how far apart the data is (range), not just the middle
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Flipside the Other-Outcome-Counter
The complement rule — find the chance it doesn't happen and subtract from 1
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Clew the Clue-Follower
Conditional probability — how chances change once you learn a new fact
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Evens the Long-Run-Settler
Expected value and the long run — results settle toward the average over many tries
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Browse all chapters → · What's distributed-narrative methodology? →
What's inside
Probability Foundations
Flip coins, roll dice, and spin spinners. Make predictions, then run the experiments and compare your guess to what actually happens. Watch the experimental pro
Compound Events
Build probability tree diagrams for events with multiple steps. What is the probability of flipping heads AND rolling a 6? Use the multiplication rule for indep
Distribution Explorer
Collect data and build histograms in real time. Calculate mean, median, mode, range, and standard deviation. See how different distributions look — symmetric, s
Sampling Lab
Discover why polling works — and why it sometimes fails. Sample from a virtual population and see how random samples represent the whole. Compare random samplin
Mentored by Chance — on-device AI, no data leaves the device.
How ChanceForge handles your kid's data
- ✅ All progress, settings, and AI-generated content stays on the device
- ✅ No analytics, no tracking, no third-party SDKs
- ✅ Free — no ads, no in-app purchases
- ✅ No personal information collected from children — in line with COPPA (updated by the 2026 FTC amendments)
- ✅ No chat with strangers — play-together rooms use a short code and preset emotes, never typed messages
For you, the grown-up
Spark & Whetstone, our free site for grown-ups, tells what ChanceForge teaches in 3 short courses.
ChanceForge runs on ForgeKit — the open-source Swift Package Manager framework that powers every Spark & Anvil app. ForgeKit ensures consistent accessibility, COPPA compliance, and design language across the portfolio, so your kid's progress and preferences feel coherent across every app they touch.
Coming to the App Store
ChanceForge is in active development. Email us to hear when it ships — no marketing, no spam, just a one-shot launch announcement.
Email me at launch