A wealthy Manhattan landlord left $20 million to his two daughters — but they can collect only on his strict terms.

Daddy Dearest real estate millionaire Maurice Laboz, who died earlier this year, doled out early-bird bonuses to his girls in his will as long as they marry right, get good jobs and don’t even think about having kids out of wedlock.

The Laboz girls — Marlena, 21, and Victoria, 17 — are set to inherit $10 million apiece when they turn 35. But they can get their hands on some of the dough beforehand if they follow Daddy’s rules for the straight and narrow. For example:

Marlena will get $500,000 for tying the knot, but only if her husband signs a sworn statement promising to keep his hands off the cash.

She nets another $750,000 if she graduates “from an accredited university” and writes “100 words or less describing what she intends to do with the funds” — with the trustees appointed by her dad to oversee her money responsible for approving her essay.

Both daughters get a big incentive to earn decent salaries by 2020. Each young woman is guaranteed to receive an annual payout of three times the income listed on their personal federal tax return. In a not-so-subtle nod to the taxman, their checks will be cut every April 15.

If the daughters have kids and don’t work outside the house, the trustees will give them each 3 percent of the value of their trust every Jan. 1. There’s one catch: The money flows only for a “child born in wedlock.”

The sisters could earn the same amount being “a caregiver” to their mother, Ewa Laboz, 58, whom their father was in the middle of divorcing. She got nothing in the will and has indicated that she will contest it.

“It’s a way to control things from the grave,’’ said estate lawyer Jeffrey Barr, who is not involved in the case. “You don’t see a lot of it, but it happens. People do it because . . . they think it’s for the good of the children.’’

Estate lawyer Oshrie Zak said the move is not surprising in this case.

“Accustomed to the control over others that their money affords them in life, the will is their last shot at controlling their loved ones,’’ he said of Laboz and other successful people.

Maurice Laboz signed the will in April 2014, about nine months before he died at age 77. He left behind a $37 million fortune.

He justified leaving his wife out of his will by citing a “prenuptial agreement, which limits her rights,” according to the document.

Ewa Laboz filed court papers last month contesting that, arguing she deserves a share of the pot because she was still married to her husband when he died.

The rest of Laboz’s fortune is set to go to charities, including The Michael J. Fox Foundation for Parkinson’s Research and Meals on Wheels.