Presidential elections have winners and losers. And it was ever (and will be) thus. But to Donald Trump, an election he doesn't win is an election that's rigged. He has said he'll only accept favorable election results, and in doing so has created the phantasm of a third option: the candidate who avoids losing by refusing to acknowledge it.

So what happens if Trump loses and refuses to concede, either because the margins are too narrow or he just feels like it? That would put us in uncharted territory: No losing US presidential candidate has ever refused to concede when the time came. But despite Trump's aspersions that the system is rigged and that voter fraud proliferates, US election law is well-studied, robust, and pretty darn comprehensive. And actually, it doesn't give a hoot if a candidate concedes or not.

Let's get this out of the way. A candidate's concession isn't legally required. And refusing to concede has no legal implications. "Not conceding is like behaving rudely at a dinner party: it’s not done," says Samuel Issacharoff, an election law expert at New York University. "But sometimes you have bad guests." So Trump can refuse to concede until he's blue beneath his spray tan, and nothing in particular will occur.

Trump can refuse to concede until he's blue beneath his spray tan, and nothing in particular will occur.

That's because every state has legal channels for resolving challenges to election results. Which is where things get complicated. "We don't have one election," says Richard Briffault, a political law expert at Columbia Law School. "We have 51 separate elections with 51 separate sets of rules." But generally, when an election is in question, two things can happen: the straight recount, or the election contest. A regular old recount doesn't make any claims of monkey business, and states have different regulations for when and how they're triggered. In South Carolina, officials will recount ballots if the margin between candidates is less than 1 percent of the vote. In Florida, the margin has to be .25 percent. In other states, a losing candidate has to request a recount. And, due in part to the law of large numbers, the initial results almost always stand.

Contesting an election is different. It's an accusation that something's amiss. Example: Bush versus Gore in Florida in 2000, which had so much controversy going on—alleged racial discrimination, ballot invalidation, butterfly ballots that made people vote for Pat Buchanan—it resulted in recounts and calls for election reform. "That's when there's a challenge to the eligibility of ballots, and it gets thrown into court," says Jim Gardner, an election law expert at the University of Buffalo. "Then what the law tries to do is determine which of the ballots were properly cast, and count those and only those."

Could Trump contest results in narrow-margined, swing states? Sure. But experts doubt whether the Trump campaign has the wherewithal to do so. "Recounts take enormous resources. You need serious lawyers, and boots on the ground," says Heather Gerken, a Yale Law School election law expert who was senior legal advisor to the 2008 and 2012 Obama for America campaigns. "It's Campaign Law 101, but he doesn’t seem to have the legal apparatus for this."

To contest an election, you need grounds to do so. That means finding real, hard factual evidence, and local and national lawyers who can advise the campaign on the best way to frame and present that evidence. And on a tight timeframe: as short as four days in some states. "You cannot wing this. You can’t just be a sore loser and say something went wrong," Gerken says. Which does not suit Trump's fact-light, fly-by-night campaigning style.

And even if Trump did find genuine skullduggery and contest election results, it might not matter. "There’s an inherent problem in election litigation," says Gardner. "Sometimes a flaw of some kind might be uncovered but nothing can be done in time to affect the election." In that case, courts might issue an injunction that would require the state or locality to get their act together by the next election.

But what about the Supreme Court, you ask? You'll recall that in 2000 the Supreme Court did (very, very controversially) stop the ballot recount in Florida, but it is unlikely to weigh in this time around. "The court was badly stung by the criticism for their actions," says Gardner. "And it's a four-four court. They're not going to act if they can’t be decisive."

This is not a banana republic. The idea that he could pull off anything like that is basically inconceivable. Issacharoff

Which leaves only one avenue for Trump, should he still be unwilling to concede: tampering with the electoral college. "He can ask the electors to vote for him instead, or try to get state legislatures to substitute a second slate of electors," says Issacharoff. "But this is not a banana republic. The idea that he could pull off anything like that is basically inconceivable."

And governments have put provisions in place to safeguard against that kind of thing. The electoral college is supposed to vote in alignment with their state. Some states have made it illegal for electors to go off ranch and vote differently than they're directed. Others can fine or remove unruly electors. It does happen. A Washington elector has already said he won't vote for Hillary, even if she wins his state. "There's never more than one in an election, and it's never mattered," Briffault says. So, if there is no provable fraud or flaw, every avenue to changing the election results is a dead end, or just illegal.

Still, any candidate refusing to accept the results of a properly conducted election is a blow to democracy. And that's why we hope that—regardless of who wins today—the loser will be gracious in his or her concession. "One hopes that, like kidney stones, this too shall pass," Issacharoff says. But if Trump does lose, it might be comforting to remember: Short of a coup d'état, there's not much he can do but grumble.