STEM
BiasForge
Run the famous experiments about how your brain fools itself — on YOURSELF. Guess the anchored number, fall for the bat-and-ball, meet the Linda problem. Each reveals the trap by name (anchoring, framing, base-rates, the peak-end rule…), tells you how sure scientists actually are, and shows the slow move that catches it. Once you can name a trick, you can beat it. No timer, no score to chase; on-device, no account. Ages 9–14.
▶ 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.
Mentored by Solon
#4b3f8f Characters who teach
Meet the cast
BiasForge's cast is your two ways of thinking, made into characters (not brain parts): Whim is the fast first impulse that jumps to the answer that FEELS right; Muse is the slow, careful second look that catches the trap. Mentor Solon keeps the studio calm — a bias isn't a failing, it's how everyone's fast brain works; naming it is how you catch it. And every finding carries a science-meter: is this solid, still argued, or a famous claim that didn't hold up?
Whim
The fast first impulse (System 1) — jumps to the answer that feels right, and walks straight into the trap so you can see it
Barnacle
Anchoring; a number you just saw drags your estimate toward it, even when it tells you nothing
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Glaze
Framing; the same facts worded two ways change what people choose
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Plenty
Base rates; how common something is overall matters, and a vivid clue makes people forget it
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Muse
The slow, careful second look (System 2) — pauses, does the one check the trap counts on you to skip, and catches the bias
Finale
The peak-end rule; we remember an experience by its most intense moment and its ending, not its total
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Solon
a bias isn't a failing, it's how everyone's fast brain works; name it and you can beat it. Always ask how sure the scientists really are.
Browse all chapters → · What's distributed-narrative methodology? →
What's inside
Learning goal
Run the famous experiments about how your brain fools itself — on YOURSELF. Guess the anchored number, fall for the bat-and-ball, meet the Linda problem. Each reveals the trap by name (anchoring, framing, base-rates, the peak-end rule…), tells you how sure scientists actually are, and shows the slow move that catches it. Once you can name a trick, you can beat it. No timer, no score to chase; on-device, no account. Ages 9–14.
Mentored by Solon — no data leaves the device.
How BiasForge 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
The grown-up side of BiasForge on Spark & Whetstone, our free site for grown-ups: The Forecast Table. They catch the mind's shortcuts; you write down how sure you are, then check.