Steven Spielberg’s “Ready Player One” could top the $50 million mark at the North American box office in its opening weekend over the Easter holiday, early estimates showed Thursday.

Warner Bros. adhered to its guidance of $45 million with a possible upside, while rivals gave forecasts in the $55 million range for the Thursday to Sunday period — indicating that a $50 million plus opening is well within reach. The studio has already adjusted its projection upward from the $38 million to $42 million range earlier in the week.

Ready Player One” opened with $3.8 million at 3,500 North American locations in Wednesday night previews and will likely dominate the domestic box office this weekend. The sci-fi fantasy expands to 4,234 locations Thursday and is launching day and date internationally in 62 markets with $3.2 million in $3.2 million in foreign grosses since opening in Tuesday previews.

Paramount’s “G.I. Joe: Retaliation” generated $2.6 million five years ago in preview showings in Wednesday night previews in 2013 on its way to a $51 million domestic opening on a four-day Easter weekend in 2013.

Based on Ernest Cline’s 2011 novel, “Ready Player One” is set both in a dystopian version of Columbus, Ohio, in 2045 and in an elaborate virtual reality world called Oasis, popular because it enables residents to escape the grim reality of their actual world. The film, written by Cline and Zak Penn, stars Tye Sheridan, Olivia Cooke, Ben Mendelsohn, T.J. Miller, Simon Pegg, Lena Waithe and Mark Rylance. Reviews have been mostly positive for “Ready Player One” with a 79% “fresh” score on Rotten Tomatoes.

“Ready Player One” is closing out what’s been a downbeat March with the North American box office struggling, off 31% for the same month a year ago, according to comScore. That follows a record February that was driven by Disney-Marvel’s “Black Panther.” The year to date as of March 27 is off 4% at $2.71 billion domestically.

The second weekend of Universal-Legendary’s “Pacific Rim Uprising,” the seventh weekend of “Black Panther” and Lionsgate-Roadside’s third weekend of “I Can Only Imagine” will be fighting for second place during the holiday weekend. “Pacific Rim Uprising” has grossed $34.7 million in its first six days, while “Black Panther” has passed the $637 million mark in 41 days, making it the fifth highest-grossing movie ever in the U.S. Faith-based “I can Only Imagine” has taken in an impressive $43 million in its first 13 days.

Two titles with moderate outlooks are opening Friday — Lionsgate’s thriller “Tyler Perry’s Acrimony” and Pure Flix’s’ “God’s Not Dead: A Light in Darkness.” “Acrimony,” starring Taraji P. Henson as a vengeance-seeking wife, is pegged to launch with $7 million to $11 million at 2,006 venues. Faith-based “A Light in the Darkness” is forecast to finish around $5 million at 1,688 sites.