What caused the change?
Labs / History
Innovation Tree
Every invention stands on the ones before it. Research points build up over time — spend them to unlock the glowing inventions whose prerequisites you already have, and watch dependent branches light up. Flip on what-if mode to erase a single invention and see how much of history stalls behind it.
Labs / History / Innovation Tree
Innovation Tree
Every invention stands on the ones before it. Research points build up over time — spend them to unlock the glowing inventions whose prerequisites you already have, and watch dependent branches light up. Flip on what-if mode to erase a single invention and see how much of history stalls behind it.
Why it matters
Why explore this?
History is about change over time and the choices that shape it. This model helps you compare causes, consequences, and patterns without treating the past as a list of dates.
Explore
Try the model
Era PrehistoryRP 24Spent 0Locked 20
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- Which three inventions can you research first, before you've unlocked anything at all? What do they have in common?
- Race straight for the Engine. What is the shortest chain of prerequisites you must unlock to get there?
- Turn on what-if mode and skip Smelting. How many later inventions stall — and does the wheel's branch survive?
- Is any single invention a prerequisite for both the Engine and Electricity? What happens to the Modern era if you erase it?
- Switch to Patient pace. Does the order you unlock things in change, now that points are scarce?
Explain
Make sense of what happened
Build an explanation with a cause, a change, and a consequence. Then identify evidence from the model and one limitation of what the model can show.
Check
Before you leave
Who or what was affected?
What can this model not tell us?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.