One-person pieces are often the hardest type of theater to bring off. Live stage work depends on conflict and no matter how talented a performer is, convincingly creating character and/or principle clashes while flying solo is a prodigious task few can handle with dexterity. There’s also the heightened economic stakes of theatre these days. Audiences pay into the triple digits and if you’re greeted with a bare stage and only one name in the cast list, expectations are going to be that much higher. The current double bill Sea Wall/A Life now at the Hudson Theater in a limited Broadway run after a hit Off-Broadway engagement at the Public last season, does offer two single acts with top-shelf talent and relatable, heart-wrenching content.

Both pieces by separate authors deal with shattering turning points and afford magnificent vehicles for two daring stars. Sea Wall by Simon Stephens (Tony winner for The Curious Incident of the Dog in the Night-Time) is heartbreaking, but the lesser of the two pieces. Tom Sturridge is Alex, an adorably rumpled chap relating his idyllic experiences of love, his gruff but lovable father-in-law, and becoming a father to the most precious daughter in the world. (We get to know more about the wife’s father than the wife herself.) The little family vacations in the dad-in-law’s perfect seaside home in the South of France. Of course with all this sweetness and joy, something tragic has to go wrong. Sturridge admirably conveys Alex’s anguish, humor, and urgent questing to find meaning in his personal tragedy. At times, the actor is so convincingly in the moment, little details such as knocking over a water bottle or not completing a sentence have shattering impact. But the tale feels incomplete and underdeveloped.

A Life by Nick Payne is much more complex and Jake Gyllenhaal delivers a brilliantly shaded performance as Abe, a man coping with the twin poles of existence—birth and death. Payne skillfully juxtaposes twin narratives of the terminal diagnosis of Abe’s father and the hilarious chaos resulting from the upcoming birth of his child. The piece opens with Abe fumbling in the dark for the light switch and apologizing to the audience for the inconvenience. Later, he frantically runs through the theater, using his iPhone for a flashlight, on an errand for his pregnant wife. Both sequences are funny, touching, frenzied and messy—just like real life. Then they are quickly followed by moments of sorrow as Abe confronts the pain of losing his dad. One minute he is desperately calming his wife through labor pains and the next dealing with funeral arrangements. Payne feelingly and seamlessly chronicles these intertwined life voyages and Gyllenhaal intensely conveys their intense dichotomy. Carrie Cracknell directs both plays with a balanced hand, eliciting the maximum of pathos and guffaws. Guy Hoare’s lighting and Daniel Kluger’s sound design  create a palpable world on Laura Jellinek’s bare set.

Meanwhile, Off-Broadway, the Main Stem comes in for a riotous ribbing in a clever, pocket-sized musical called Broadway Bounty Hunter. Combining equal parts Quentin Tarantino and Gerard Alessandrini of Forbidden Broadway fame, the clever book by Joe Iconis (Be More Chill), Lance Rubin and Jason Sweettooth Williams parodies schlocky tuners and violent exploitation flicks without mercy. Veteran Annie Golden (Hair, Assassins) stars as a theatrical version of herself, a stage performer of a certain age endlessly auditioning and rejected by snooty casting directors only interested in young blood. Incredibly, she is recruited by a mysterious ninja-like woman to join a squad of bounty hunters. What follows is a wacko ride from a South American brothel back to a New York opening night of a ditzy show called Young People: The Musical. The inventive score by Iconis melds 1970s funk with Broadway rhythms.

Like the best Carol Burnett Show sketches, Bounty Hunter incisively skewers show-biz conventions. In addition to the golden Golden, the cast also includes sexy Alan H. Green as a Shaft-like hero, Brad Oscar as a deliciously villainous drug pusher-pimp-theatrical producer, and Christina Sajous as a fierce prostitute. Directed and choreographed with economic skill by Jennifer Werner, the ensemble commits to this bizarre universe with utmost seriousness making it all the funnier.

Sea Wall/A Life: Aug. 8—Sept. 29. Hudson Theater, 141 W. 44th St., NYC. Mon—Tue 8pm, Wed 2PM & 8pm, Thu—Fri 8pm, Sat 2pm & 8pm. Running time: one hour and 45 mins. including intermission. $59—$315. (855) 801-5876. www.thehudsonbroadway.com.

Broadway Bounty Hunter: July 23—Aug. 18. Greenwich House Theater, 27 Barrow St., NYC. Tue—Thu 7pm, Fri 8pm, Sat 2pm & 8pm, Sun 2pm & 7:30pm. Running time: two hours and 20 mins. including intermission. $49—$129. www.ovationtix.com.