UK General Elections Explained
A UK general election is not one single national contest. It is 650 separate constituency elections, each choosing one Member of Parliament for the House of Commons.
That simple fact explains much of what makes British elections interesting: a party's national vote share can look very different from its share of seats, small changes in marginal constituencies can have a large effect on the result, and a party can sometimes form a government without winning an outright majority of all 650 seats.
Use these explainers to understand the real system, then put the ideas into practice in Road to Number 10.
About the simulation
Road to Number 10 is a fictional educational campaign simulation.
Its polling positions, campaign events and projected election outcomes are designed for the game and should not be treated as statements about current voting intention or predictions of a future UK general election.
The explainers below describe the real UK Parliamentary electoral system using independent and primary sources.
Start with the basics
How does a UK general election work?
The UK is divided into 650 constituencies. Voters choose a candidate in their constituency and the winner becomes the area's MP.
UK general elections explained →
How does First Past the Post work?
The candidate with the most votes wins the constituency — even if they receive less than half of all votes cast.
First Past the Post explained →
How many seats does a party need to win?
326 is the straightforward numerical majority of all 650 Commons seats, but government formation is ultimately about commanding the confidence of the House of Commons.
Seats and majorities explained →
Understand the battleground
What is a marginal seat?
A marginal is a constituency where the winner is only a relatively small number or share of votes ahead of the runner-up.
What does electoral swing mean?
Swing measures how party support changes between elections. The traditional two-party calculation averages one party's gain and another party's loss.
What is tactical voting?
A tactical voter supports a candidate who is not necessarily their first choice because they believe that vote is more likely to influence the constituency result.
From votes to government
What is a hung Parliament?
A hung Parliament occurs when no single party has an overall majority of seats in the House of Commons.
How is a government formed after an election?
The key constitutional test is whether a government can command the confidence of the House of Commons. A majority government is only one possible outcome.
Government formation explained →
Polls, projections and FPTP
How do opinion polls and seat projections work?
Polls estimate voting intention from samples. Seat projections then use assumptions and models to estimate how those votes might translate into 650 local contests.
Polls and projections explained →
Why can a party win more votes but fewer seats?
FPTP rewards where votes are won, not simply how many votes a party receives nationwide.
Put the ideas into practice
You understand the rules. Now run an eight-week campaign, balance polling and resources, target marginal seats and see how your votes translate into 650 Commons seats.
Road to Number 10 is a fictional educational simulation. The scenario is designed to demonstrate electoral concepts rather than forecast a real election.