President Muhammadu Buhari is not on the ballot this time, as he will complete the two terms he is constitutionally allowed to serve in May. The electorate will choose a new president to address the many issues Nigerians are trying to overcome.

Furthermore, voters will also choose new senators and members for the House of Representatives in this election, which could potentially result in a complete shake-up. On March 11, governorship races will follow.

Here's what else you need to know about this election:

Who is running?

A total of 18 candidates are vying for the presidency. Some polls suggest that the main contest is between Bola Tinubu from the ruling All Progressives Congress (APC), Atiku Abubakar of the main opposition People's Democratic Party (PDP) and the Labour Party's Peter Obi, who even is leading in some polls.

However, a lack of reliable polling makes it difficult to make any reliable predictions. The only thing that is certain is the fact that the ruling party has a major advantage: It is able to use the state apparatus to mobilize support.

Bola Tinubu and Atiku Abubakar have significant power bases across Nigeria, while Peter Obi appears to be banking on the growing frustration over the economy and insecurity in the country in hopes of turning voters against the two major parties.

What are the main issues?

Nigeria, which is Africa's top oil producer, is a key Western ally in the fight against Islamist insurgents in West Africa. The top issue for many Nigerian voters, however, is the overall threat of spreading insecurity in the country. From kidnappings for ransom in the northwest to a 13-year Islamist insurgency in the northeast, separatist violence in the southeast, and decades-old ethnic tensions mostly between herders and farmers in the north-central region, Nigeria is rife with instability.

Additionally, inflation has reached its highest in nearly two decades, hitting double-digit figures, and many Nigerians say that life is harder now than when Buhari took office in 2015. The naira currency has plunged to record lows as unprecedented oil theft knocked crude exports last year; all the while, corruption also remains at endemic levels.

As the economy suffers, hundreds of Nigerians have decided to leave the country in a punishing brain drain which is stretching a weak healthcare system and disrupting services from banking to tech.

What do political parties offer in response?

There are no clear ideological differences between the two major parties. In fact, rather than ideology, there are other factors at play: competition for dwindling oil revenues, patronage, and ethnic rivalries typically take on bigger roles in Nigeria's elections.

Obi, who left the PDP last year and was Abubakar's running mate in 2019, has cast himself as a reformist willing to overhaul Nigeria's political system. But on policy, there is little difference between the main candidates.

Tinubu, Abubakar, and Obi have all made the revival of the economy and the ending of insecurity top priorities, promising better pay for security forces and more military equipment to defeat insurgents.

Their manifestos say they would scrap a fuel subsidy that cost $10 billion (€9.34 billion)  last year. However, they differ on how quickly they plan to do this.

They have all promised to reform the foreign exchange market and to invest more in education.

How will the election take place?

Some 93.4 million people have registered to vote, of whom three-quarters are between the ages of 18 and 49. However, the challenge for the parties will be to actually get the votes: Many younger Nigerians say they do not relate to the two major-party candidates, who are both septuagenarian political veterans.

In fact in 2019, voter turnout was only 35%, electoral commission figures show.

Observers have expressed concern over the fact that Nigeria has a long history of electoral fraud. This year, however, the Independent National Electoral Commission (INEC) will be using a Bimodal Voter Accreditation System (BVAS) to identify voters through fingerprints and facial recognition, hoping that this will curb any attempt at rigging the election.

On voting day, results will be pasted outside polling stations and sent through BVAS to an INEC portal in the capital  Abuja. They will be displayed on the portal in real-time, allowing the public to view them as well.

Official results are expected to come in within five days. After that, the candidate with the most votes will be declared the winner if they have at least one-quarter of the vote in two-thirds of Nigeria's 36 states and the capital. Otherwise, there will be a run-off between the two top candidates within 21 days.

Security concerns ahead of poll

Despite this tightly organized regimen, there are lingering security concerns. Last week, authorities directed all universities to shut down for nearly three weeks ahead of the presidential elections, citing security concerns.

The National Universities Commission said these included concerns about the security of staff, students, and property of institutions. The decision to close the country's more than 200 universities from February 22 to March 14 followed "extensive consultations with the relevant security agencies."

Nigeria is battling various armed groups in its northwestand southeast, while overstretched security forces continue to also fight decade-long extremist violence in the northeast. In recent years, gunmen have targeted universities in the troubled northern region, with hundreds of students abducted and later freed, but sometimes only in exchange for ransom payments.

In addition to ensuring the safety of students, the university closure will also allow people enrolled at faculties in other parts of the country to return to where they're registered to vote, Haruna Lawal Ajo, the university commission's director of public affairs, told Associated Press (AP).

Nigeria's electoral law only allows people to vote from where they're registered. With students comprising 28% of the electorate, the planned closure could boost election-day turnout.

With additional information from Reuters and AP.