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Pick a district
Choose one of the 10 district colors. Each district must hold exactly 10 voters.
Free redistricting game
Free Gerrymandering Simulator
A gerrymandering simulator lets you draw election districts on a map of voters and see how the line placement alone changes who wins. In this state Blue has 60% of the vote, yet the same voters can elect 10, 6, or only 4 Blue representatives.
Want to hear both sides argue about redistricting? Watch the AI bots debate it.
Draw your districts
Try a ready-made map
How to use the gerrymandering simulator
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Paint the map
Tap or drag across voters to assign them. Districts must be one connected piece.
3
Watch the seats flip
The scoreboard updates the seat count, wasted votes, and efficiency gap as you draw.
Gerrymandering questions
What is gerrymandering?
Gerrymandering is drawing election district lines to give one party or group an advantage. The same voters can elect very different delegations depending on where the lines go.
What are packing and cracking?
Packing crowds the other side's voters into a few districts they win by huge margins. Cracking splits their remaining voters across many districts so they fall short everywhere else.
What is the efficiency gap?
The efficiency gap compares each party's wasted votes: every vote for a losing candidate plus every winning vote beyond the 50% needed. The difference divided by total votes shows which party the map favors. Gaps above about 7% are often cited as a sign of partisan gerrymandering.
Can a party win most seats with a minority of votes?
Yes. In this simulator Red has 40% of the votes but can win 6 of 10 seats by packing Blue voters into four lopsided districts and winning six others narrowly.
Is gerrymandering legal?
Racial gerrymandering can violate the Constitution and the Voting Rights Act. In Rucho v. Common Cause (2019) the U.S. Supreme Court held that partisan gerrymandering claims are not for federal courts, so limits now come from state constitutions, state courts, and independent redistricting commissions.
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