You would think that after intercepting broadcasts of science-fiction movies for decades, extraterrestrials would know that if they want to conquer us Earthlings they need to take out our lovably rebellious rogues and our unexpectedly heroic nerds. Certainly the makers of “Battleship,” a cacophonous new special-effects extravaganza inspired (sort of) by a game youngsters once played with pencils and graph paper, have studied those old movies. You can tell because they seem to have borrowed rather a lot from them. “Battleship,” the latest filmmaking project of the Hasbro toy company, has a plot as unambitious as a macaroni dinner, familiar and easy to eat and not particularly nutritious. It is likely to remind you variously of “Independence Day,” “Armageddon,” “War of the Worlds” and assorted other space-based yarns. Which of course means there’s never much doubt about how it will end. The United States Navy is conducting training exercises along with allies off Hawaii when unfriendly visitors come calling in gigantic spacecraft that land in the ocean. The naval weaponry seems hopelessly inadequate to the task of defending against the invaders. But, hallelujah, a rule-breaking junior officer (Taylor Kitsch) and an admiral’s daughter (Brooklyn Decker) and several other makeshift heroes have greatness thrust upon them and eventually find ways to overcome the seemingly invincible. Even Rihanna, playing a petty officer who handles the big guns, helps out (and she’s just fine in the rather generic role). No one who goes to this movie, directed by Peter Berg, is likely to care about the lack of finesse in the script and the acting, but a little bit more effort in either area would have made this a much better film. Most of the roles seem underplayed. Heck, if you’re going to build your story around that rogue cliché, your main guy needs to be pretty roguish. Mr. Kitsch is too bland to be memorable, a description that also applies to Liam Neeson as the not-crusty-enough admiral and most of the secondary members of the world-saving crew. They include Jesse Plemons, who was so appealing in “Friday Night Lights” on TV but here comes across as annoying. If borrowed plots and lazily constructed characters weren’t enough, the film also indulges in shameless button-pushing, with greatest-generation homages and shout-outs to injured veterans of more recent wars. It all builds to a plot twist near the end that is improbable even for a science-fiction tale. If you find this absurd turn of events stirring, then this movie is for you. But you might instead end up giggling, which does not appear to be what the filmmakers were going for. What does any of this have to do with the game Battleship? You remember Battleship: the sink-or-be-sunk contest involving ships on a grid, played at first on paper, then as a board game and more recently on video screens. For most of its length this film bears no resemblance to the game, but eventually a moderately ingenious way is found for the fight against the aliens to at least suggest the old you-sunk-my-battleship war of wits. It’s a nice touch in a movie that doesn’t have many of them but will make millions of dollars anyway. “Battleship” is rated PG-13 (Parents strongly cautioned). Because even against space aliens, war is hell. Battleship Opens on Friday nationwide. Directed by Peter Berg; written by Jon Hoeber and Erich Hoeber, based on Hasbro’s Battleship; director of photography, Tobias Schliessler; edited by Colby Parker Jr., Billy Rich and Paul Rubell; music by Steve Jablonsky; production design by Neil Spisak; costumes by Louise Mingenbach; produced by Brian Goldner, Scott Stuber, Mr. Berg, Sarah Aubrey, Duncan Henderson and Bennett Schneir; released by Universal Pictures. Running time: 2 hours 11 minutes.