Israelis are voting in their fifth election in four years in a tight race that pits centrist Prime Minister Yair Lapid against right-wing former premier Benjamin Netanyahu, with an array of smaller parties that will set the shape of the next government.
Polls suggest Netanyahu's Likud party and its allies from the far-right Religious Zionism party and the religious United Torah Judaism and Shas parties could win 59-60 seats, leaving him just shy of a majority in the 120-seat Knesset.
Lapid's centrist "There is a Future" party and likely partners, including Defence Minister Benny Gantz's National Unity, the United Arab List and the left-wing Labour and Meretz parties may secure 56 seats.
The left wing Arab-led Hadash-Ta'al party, has said it would not join a government but it could help Lapid shore up an anti-Netanyahu camp.
With a strong possibility that no clear winner emerges after the polls close, weeks of coalition negotiations will likely ensue with a failure leading to new elections.
Here are some possible scenarios following Tuesday's vote:
Netanyahu wins a majority
If Netanyahu's bloc wins 61 or more of the Knesset's 120 seats, he will likely opt for a coalition government that may be the most right-wing in Israel's history, including ultra-nationalist Itamar Ben-Gvir's Jewish Power party, along with pro-settler Religious Zionism.
Such a formation would likely embitter Palestinians and test Israel's relations with the United States, other allies and Arab countries with which it has diplomatic relations.
Some analysts have said that if Netanyahu wins a narrow majority and forms such a government, it would not last long.
In the latest opinion polls, a few of the smaller anti-Netanyahu parties were teetering on the electoral threshold. If any of them fall short and fail to make it into the Knesset, that would increase Netanyahu's victory chances.
Lapid secures majority
If Lapid's bloc of allied parties comes out ahead of Netanyahu, he will likely try to form a similar coalition government to the one he heads now, spanning left to right. In September, Lapid backed a two-state solution with the Palestinians but prospects for talks remain dim and the West Bank has seen some of the worst violence in years.
Lapid's chances would be boosted by a particularly high turnout among Israel's Arab minority and a low turnout in traditional Likud strongholds.
No clear majority for either Netanyahu or Lapid
If no clear majority emerges, either Netanyahu or Lapid could be tapped by President Isaac Herzog to try to form a government. If one fails the other would get a shot. A double failure could even see a third candidate, like centrist Gantz, get a chance to patch a government together. If the deadlock is not broken, there will be another election. In either case, Lapid would remain in office as head of a caretaker government until a new prime minister was sworn in.
Lapid or Gantz join a Likud coalition
Remote but not impossible. Although both Lapid and Gantz have ruled out serving under Netanyahu, who is on trial on corruption charges he denies - Israeli politics is unpredictable.
The need to overcome the protracted political deadlock may persuade the two centrist leaders to join Netanyahu's Likud in a coalition that would not include the firebrand Ben-Gvir.