Define the term “buffalo soldier.”

A) A black U.S. soldier (and often former slave) sent west after the Civil War to bravely fight American Indians and further expansion.

B) A black U.S. soldier responsible for the deaths of thousands of peace-loving American Indians in the late 19th century.

C) A Bob Marley song pseudo-reggae fans played (but didn’t understand) in their dorm rooms, circa 1984.

D) Depends whom you ask.

You have to do your homework to understand Penumbra Theatre’s new play, “Grandchildren of the Buffalo Soldiers.”

The work, written by Assiniboine playwright, William S. Yellow Robe Jr., requires some knowledge of the subject matter – more than listening to the song “Buffalo Soldier” on repeat can provide.

But after the history lesson, you can’t expect that this play will be a historical play. You have to let it be what it is: a realistically complex look at race, family and identity.

“Grandchildren” is more about one family’s coming to terms with their ancestry than about a general legacy. In fact, the play focuses almost entirely on the American Indian (or “Indin” as it is pronounced in the play) side of the family tree, with little mention of buffalo soldiers at all.

Though dialogue and the general plotline give some explanation of the past, the play is really about the present.

Craig Robe (James Craven) is a sort of American Indian prodigal son, returning home to the reservation and his family after years “on the road.” His sister, Sugar (George Keller), now has a daughter named

August (Maya Washington), whom he has never met. August’s naming ceremony, an Assiniboine rite of passage, inspires Craig’s return.

Meanwhile, his two brothers have made lives for themselves on the reservation. Brent (Jake Hart) considers himself a “full-blooded Indin,” despite their father’s black heritage, and has three children. Brent’s identity is troubling for Craig and hints at his reasons for leaving.

As Craig, Craven is like a pile of tinder during a drought – ready to go up in flames at the slightest provocation.

It’s clear from the start that he’s angry – angry because his family has settled into a routine life on the “rez,” among ancestors of those who mocked his grandfather and father’s black ancestry. Growing up, Craig took the most criticism for being a “breed,” or one who is not 100 percent American Indian.

Through Craig, Yellow Robe Jr. addresses an issue common among those of multiple ethnicities – having to constantly “prove” one’s identity through actions or appearance.

By the second half of the play, Craig criticizes the practice, saying to Stevie, “What we do to be Indin or don’t do because it might make us look less Indin is a sickness beyond any thinking.”

Fortunately, the seriousness of this subject (and its resulting family feud) is balanced skillfully with the innocence and humor of other characters.

Elmo (freedome bradley) is Craig’s youngest brother, a mentally disabled man coping with his wife’s abandonment.

It is Elmo who is the primary source of comic relief and overall perspective in the play. He takes on the classic “fool-as-unacknowledged-sage” prototype. What could be a stereotypical characterization of someone with special needs ends up enlightening and hilarious. Elmo relentlessly questions an annoyed Craig on the role of white people in his life (“Those white people did get to you, didn’t they?”) and re-enacts their father’s favorite knee-slapping dance.

And though a SpongeBob backpack and glittery jeans cannot make August look her character’s preteen age, Washington adds energy and optimism to the show. She balances Craig’s anger with her singsong voice and smile.

There are moments of strangeness in the show, as there are in any family. A scene beginning with a flirtatious kiss between Sugar and her husband, Stevie, feels weirdly uncomfortable by its end.

Stevie chasing his wife around the kitchen and joking about lifting his wife’s makeshift “teepee” (her apron) feels a bit like watching your aunt and uncle make out. Though they’re not your parents, it’s still alarming.

It would have been enough for playwright Yellow Robe Jr. to show audiences a living, breathing portrait of an American Indian family, a demographic mainstream American entertainment ignores. Instead, his play raises questions about how we come to be who we are and the choices and factors that create our identities.

The many quandaries make for an interesting, if not overwhelming, assignment.