STORY: All four candidates in Iran's presidential election are loyal to the supreme leader.
So the next president is unlikely to bring a major shift to the Islamic Republic.
Ayatollah Ali Khamenei, the 85-year-old who has been supreme leader since 1989, holds the reins of power.
And a hardline watchdog vetted the candidates, presenting voters with little real choice.
Public discontent, especially among Iran's youth, has kept voters away in recent elections.
And this one also coincides with rising regional tensions, with conflict raging between Israel and two armed groups backed by Iran - Hamas in Gaza and Lebanon's Hezbollah.
:: Will anything change?
A new president won't change Iran's backing for militant groups, its policy on Iran's nuclear program or relations with the West.
Khamenei calls the shots on top state matters.
POLITICAL UNIVERSITY STUDENT, AMIR ALI ZAMANI: "No, I don't think it matters. Foreign policy has always remained the same, and this year will be no different from previous years."
But the president does run day-to-day government and can change the tone of Iran's foreign and domestic policy.
All candidates have promised to fix an ailing economy that's beset by mismanagement, corruption and sanctions and a source of deep frustration for Iranians.
More importantly, the outcome could influence the succession to Khamenei.
:: Who are the candidates?
So who is standing?
The presidency was left empty by the death in May of President Ebrahim Raisi in a helicopter crash.
Three of the candidates are hardliners and one is a low-profile comparative moderate.
Mohammed Baqer Qalibaf is one of two hardline frontrunners.
He's the current speaker of parliament and a former Revolutionary Guards commander.
Civil rights activists know Qalibaf for crushing protests - first as national police chief, when he personally beat protesters...
Then as Tehran mayor for 12 years, when hell helped suppress months of unrest that shook the establishment in 2009.
The other frontrunner is Saeed Jalili.
He's best known abroad as a former chief nuclear negotiator for five years from 2007.
Jalili lost his leg fighting in the Iran-Iraq war in the 1980s and declares himself a pious believer in Iran's system of Islamic government.
The third hardliner is Mostafa Pourmohammadi, the only cleric left in the race.
He's a former interior minister and deputy intelligence minister.
Human Rights Watch, in 2005, documented Pourmohammadi's alleged role in the execution of hundreds of political prisoners in Tehran in 1988.
Allegations he has never publicly addressed.
Massoud Pezeshkian is the only relative moderate among the four, backed by the pro-reform camp.
"Just as we can talk to each other, we can also learn to talk to our neighbours and rest of the world. We cannot fight everyone, we should not fight, we should not show aggression to others."
Pezeshkian was vocal in criticizing the Islamic Republic for its lack of transparency over Mahsa Amini...
:: Released December 2022
... a young Iranian Kurdish woman whose death in custody sparked several months of unrest in 2022.
Some activists at home and abroad called for a boycott of the election, saying voting served to legitimize the Islamic Republic.
