The Electoral College vote is usually a boring formality. Yet after an unusual presidential campaign that has shown time and time again that the wholly unexpected can become reality, there will be an unusual amount of attention to what happens when 538 people will meet Monday to select the president of the United States.

For weeks now, many have been calling on the electors to pick the candidate who won the popular vote, calls that have only grown recently amid revelations that the intelligence community believes Russia interfered in the election to help Donald Trump. Everyone agrees, however, that it is very, very unlikely that anything out of the ordinary will happen Monday. But, hey, we’ve said that a lot this year only to have to admit that all predictions were wrong, so might as well be prepared for the unexpected. Here’s a rundown of the process that begins Monday and what can happen.

How does someone become an elector?

The name electors may bring up images of chosen people, picked out of the population for their sage wisdom. The truth is far more mundane. Really, they’re just people chosen by state political parties. The process to become an elector varies by state. Some electors are picked at congressional-district and state conventions, while in other states it is the party leaders who pick the electors. There are some well-known names in the mix (Bill Clinton is an elector, for example), but most of the electors are far from household names.

How many electors are there?

The total is 538, as each state has an elector for each House and Senate seat in Congress, including three electors from the District of Columbia. California has the most electors with 55, while states with small populations such as Montana and Alaska get three each.

What is the preliminary electoral count?

Hillary Clinton won almost 2.9 million votes more than Donald Trump, according to the latest tally. But Trump won the Electoral College, 306-232. That means 37 Republican electors would have to change their vote in order for there to be a shot of denying Trump the presidency, yet it likely wouldn’t be enough (more on that later).

Where and when will electors meet?

All electors will be meeting Monday Dec. 19, usually in their respective state capitols, to cast their ballots for president and vice president. The meeting time varies according to each state.

Will the electors receive an intelligence briefing before voting?

Seems highly unlikely at this stage. Some 80 (mostly Democratic) electors have signed a letter calling for an intelligence briefing on Russian hacking during the election. But a statement from the Office of the Director of National Intelligence pretty much poured cold water on the prospect of intelligence briefings to a set of people who mostly don’t even have security clearances. “The president has recently directed the intelligence community to conduct a review of potential foreign interference in presidential elections dating back to 2008,” notes the statement issued Friday. “This effort is ongoing and involves sensitive classified information. Once the review is complete in the coming weeks, the intelligence community stands ready to brief Congress and will make those findings available to the public consistent with protecting intelligence sources and methods.”

What do the electors actually do when they meet?

That also varies state by state (sensing a pattern here?), with some treating it more like a bureaucratic hurdle, while others make a big show out of the whole thing. The one thing they all have in common is that each elector gets two votes: one for president, one for vice president. Each elector has to sign six certificates, two for the National Archives, two for the secretary of state, and one to a local judge. The most important “certificate of vote” is the one sent to the president of the U.S. Senate, in this case Vice President Joe Biden.

What are some activists calling on electors to do?

In short, become what are known as “faithless electors,” as those who ignore their state’s vote are known. As you might imagine, it is really rare for this to happen. There have only been 157 faithless electors in the history of the country and the last time there were more than two in one election was in 1832. But that isn’t stopping those who are calling on 37 Republican electors to switch up their votes.

A number of high-profile actors, including fictitious president Martin Sheen, even filmed a video calling on electors to cast their vote for anyone other than Trump.

Lawrence Lessig, a Harvard University law professor working in one of the many efforts to stop Trump from getting to the White House, said last week there were “at least” 20 Republican electors who were “seriously considering” defecting. He provided no evidence for his claims.

So electors can really vote for anyone they want?

Eh, sort of. Technically speaking electors can do whatever they want. For practical purposes though, 29 states have laws that force electors to vote according to their state’s popular votes, while others have also made other informal pledges to their party. Some states even stipulate that faithless electors can be fined or disqualified from participating in the process. Some consitutional experts argue that electors are free to do whatever they like, and truth be told, the Supreme Court has never ruled on whether it’s constitutional to enforce laws forcing electors to follow their state’s popular vote.

Is it likely that lots of Republican electors will defect?

No. So far, only one (Chris Suprun of Texas) has said he will not vote for Trump. The Republican National Committee has carried out counts and seems pretty confident that Supurn will be the only defector. The Associated Press talked to more than 330 electors from both parties and unsurprisingly found “little appetite for a revolt.”

When and how will the electoral votes be counted?

The formal tallying of the electoral votes will take place on Friday, Jan. 6, when lawmakers will meet at 1 p.m. Vice President Joe Biden, who is the outgoing president of the Senate, is likely to head up the count and will therefore be responsible for announcing the winner.

Are the lawmakers mere spectators during the count?

Not quite. And this is where faithless electors could come into play, as lawmakers can raise objections to votes, whether by individual electors or entire states. That’s when any vote that doesn’t match up with the state’s results could theoretically be thrown out.

What happens if Trump really fails to gather 270 electoral votes?

Yes, it’s unlikely, but if electors really do revolt it would be up to the Republican-controlled House of Representatives to select the president from the top three candidates. The top two are easy: Donald Trump and Hillary Clinton. Who’d be the third? The one who will get most votes from faithless electors, so it could be, for example, John Kasich. If the House fails to gather a majority for any one candidate, the decision would then go to the Senate.

And then that’s it?

Yep, once all votes are carried out and objections are resolved, the results are considered final, and the winner will be sworn in as president on Jan. 20.