The Brexit ballot is amazingly simple. Why can’t US ballots look like this?

The United Kingdom votes today on whether it should remain in the European Union — a huge decision for its citizens.

The outcome is uncertain, and the campaign itself has been filled with troublesome and horrifying events, including supporters of leaving using ugly, racist rhetoric and a member of Parliament getting murdered last week.

But there’s one part of the Brexit vote that the US could gain a lot from imitating: It has an extremely clear, easy-to-understand ballot.

The question is written in plain language: “Should the United Kingdom remain in the European Union or leave the European Union?” And while it’s a yes-no question, the options make it perfectly clear which one you’re choosing and how you should do it. (The Scottish referendum ballot in 2014 was even clearer: “Should Scotland be an independent country?”)

Compare that with how Maryland asked voters in 2012 if they wanted to allow a new casino in Prince George’s County and allow existing casinos to offer table games as well as “video lottery” games played on screens:

Or take how Austin asked this year about whether Uber and Lyft should be allowed to operate within city limits. The proposition doesn’t mention ride hailing or taxis at all:

This isn’t just an aesthetic issue. Confusing ballots in the US — a category that includes obscure wording and bad design — lead to tens of thousands, maybe hundreds of thousands, of votes being thrown out without being counted, according to a 2008 report from the Brennan Center for Justice. The way ballot questions are phrased can actually obscure what voters are being asked to approve.

A study of more than 1,200 state-level ballot questions that voters across the US were asked to approve between 1997 and 2007 found that, on average, they were written at a 17th-grade level — in other words, you’d need more than a four-year college degree in order to understand what you were being asked to vote on.

In response, many voters just skipped those questions altogether: A more complex ballot question led to a 5 percent decrease in participation. On about one-quarter of all ballot questions studied, that was larger than the margin between victory and defeat. Confusing language actually could have changed the outcome of the race.

Even simplifying the instructions voters are given makes a difference. Two studies comparing traditional ballots with ballots written as clearly as possible found that voters participating in a simulation made fewer mistakes using the clearly written ballots.

All it took was writing like a real person — replacing, for example, “Click the box of the candidate for whom you desire to vote” with “To vote for a candidate of your choice, click that person’s name.”

How the United Kingdom will vote on Brexit is too close to call. But at least it’s safe to assume that voters know what they’re being asked — something that isn’t always certain in the US.