How Leaders Are Chosen

An interactive guide to voting systems worldwide

Explore Systems
Voting systems are the rules that determine how votes are cast, counted, and turned into outcomes. Whether choosing a single leader like a president or filling every seat in a parliament, the voting system shapes not only the result — but the nature of political power itself.

Voting systems are designed to answer questions like:

  • How many winners will there be?

    One president, a few council members, or an entire legislature?

  • How do voters express their choice?

    Pick one, rank several, or score each candidate?

  • What's needed to win?

    Just more votes than others, or an absolute majority?

  • How closely should results reflect the overall vote share?

    Proportional representation or winner-takes-all?

How voting systems are grouped

There’s no single “natural” map of voting methods. This is one practical way to group them—each category highlights different design goals and trade-offs.

Plurality Systems

Most votes wins – not necessarily a majority

System Features

Different voting systems can be described in terms of their properties: things like majority guarantees, how votes are tallied, or whether spoiler effect occurs. The Features page collects these building blocks, and as the project grows, more will be added.

Ballot Types

Each system also meets voters through a ballot: the physical paper or digital interface where choices are marked. The Ballots page shows a growing collection of examples.

Explore Voting Systems

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