That can mean chocolate seders, child-oriented seders, hunger-awareness seders, and communal seders.
"You find a way to hold on to the must-haves and add the creative," said Rabbi Roni Handler, editor at Ritualwell, a website that highlights traditional and innovative Jewish rituals.
Traditionally, seders on the first and second day of the holiday have equal religious significance, although Jews' level of observance may determine whether they attend two or just one, rabbis say.
The two-seder tradition is rooted in the uncertainty in ancient times about when the holiday began on the religion's lunar calendar.
Witnesses watched for the start of a new moon - which determined the beginning of the month - and carried the news to the court at the Temple in Jerusalem, said Saul Wachs, chair of the education department at Gratz College in Melrose Park.
But Jews who lived far from Israel might not hear the news in time to be sure which day was the actual start of the month: the day they heard the news or perhaps the day before. By extension, the start of the holiday was also in doubt.
To cover all bases, "they celebrated two days," Wachs said. It is a Passover tradition only outside Israel, where Jews attend one seder.
During the seder, participants follow a prescribed order of the Passover meal outlined in the Haggadah book. Symbolic foods are eaten, hymns are sung, prayers are said, and the freedom story is told.
Traditional Jews stick to the traditional, unabridged service that can last past midnight. But the second seder can still be more than ho-hum when tradition is supreme, said Rabbi Albert Gabbai of Congregation Mikveh Israel, an orthodox synagogue in Old City.
"The first day is family and friends," Gabbai said, "The second day, people want change. You might go to a communal seder, with different people, strangers, even non-Jews. You discuss the Exodus from different points of view. It's exciting."
At Maura Sostack's house, the second seder will be casual vegetarian with an abridged ritual.
Jeans are OK, and the cuisine was to be plant-based, until a guest volunteered to bring salmon.
"I think I heard a sigh of relief after people found out there would be salmon," said Sostack, of South Philadelphia. "I bet they were thinking, 'Oh, we're going to have to go out and get something to eat after this seder.' "
Rabbi Sandra Berliner of the Klein Jewish Community Center in Philadelphia, is hosting two seders at her house, led a third for 150 at the center on Wednesday, and will have led six other communal seders by the holiday's end.
She is hosting 12 guests the first night and 30 the second. That second night's dinner always includes the evolving membership of two families that she has been friends with for nearly 30 years.
"We take the seder seriously. We ask questions. We add songs and maybe one or two new customs to shake things up," Berliner said.
For the Molish family of Maple Glen, two seders at home may be too much. Richard and Ilean Molish host the first night and go to their daughter's on the second.
"It's a lot of work," Richard Molish said of Passover preparation. His daughter's dinner will be breezier and more informal.
Sometimes the second night can mean focusing on a specific part of the liturgy or discussion, said Rabbi Sue Levi Elwell of Philadelphia, a retired rabbinic director with the Union for Reform Judaism.
Elwell, a pioneer in the development of the feminist seder, has co-written a new Haggadah supplement that urges participants to consider the issue of mass incarceration in discussion of the Israelite freedom story. The supplement recommends a symbolic lock and key be added to the seder plate.
"These ancient themes are being lived out by people today," Elwell said.
On Tuesday, Temple Beth Hillel-Beth El in Wynnewood will host its first second-night seder in more than 20 years.
The synagogue wanted to give people a break from the hard work of cleaning and cooking to prepare for Passover and provide an alternative for people who may not have a place to go on the second night, said Rabbi Neil Cooper.
"People are busy, and it's hard for families to get together," Cooper said. "We're going to try to make it easier and hopefully have a lot of fun."