Plot

Three actors accept an invitation to a Mexican village to perform their onscreen bandit fighter roles, unaware that it is the real thing.

Three out-of-work silent-movie actors are accidentally drawn to a Mexican village that is being harassed by a gang of outlaws. The three--'Ned Nederlander', 'Lucky Day', and 'Dusty Bottoms'--play 'Lone Ranger' types in their movies, but must play their parts for real now.—Rob Hartill

When silent film stars Lucky Day, Dusty Bottoms, and Ned Nederlander get fired, they take a job offer from Mexico: doing a show with El Guapo, supposedly the most famous actor there. Traveling there in hope of getting good money, they arrive only to learn that El Guapo is not an actor, but a cruel gang leader suppressing people. He abducts the mayor's beautiful daughter Carmen to be his wife to avenge the people's cries for help. Now, all hopes of the village folks rest on the weak shoulders of three minor-talented actors who can't just walk off the set this time.—Julian Reischl <julianreischl@mac.com>

In 1916, the notorious bandit El Guapo (Alfonso Arau) and his gang of thugs are collecting protection money from the small Mexican village of Santo Poco. Carmen (Patrice Martinez), daughter of the village leader, searches for someone who can come to the rescue of her townspeople. She goes to a town bar looking for sharpshooters who can help her against El Guapo. But nobody is willing to step up. One shooter steps forward, but he wants sexual favors from Carmen in exchange for his help.

While visiting a small village church, she remains to watch a silent film featuring "The Three Amigos" and how they team up to save a Mexican village from oppression of bandits. Lucky is an expert with Lasso, Ned is a gunslinger, and Dusty is fast with knives. In the film, they refuse payment from the villagers, rather saying that justice is their reward. Carmen finds the address of the Three Amigos, from the wagon that was transporting the film tape across Mexico. Believing them to be real heroes, Carmen sends a telegram to Hollywood asking them to come and stop El Guapo, in exchange for 100,000 Pesos. However, the telegraph operator edits her message down since she has very little money to pay for it. The message reads "You are Great. 100,000 Pesos to come to Santo Poco and put on a show. Stop the infamous El Guapo".

Meanwhile, Lucky Day (Steve Martin), Dusty Bottoms (Chevy Chase), and Ned Nederlander (Martin Short) are Hollywood silent film actors who portray the heroic Amigos on screen. When they demand a salary increase, studio boss Harry Flugleman (Joe Mantegna) fires them. He has them evicted from the studio mansion, banned from his lot, and the clothes they borrowed from the wardrobe repossessed. Shortly afterward, they receive Carmen's telegram but misinterpret it as an invitation to make a film with El Guapo (they misunderstand the word "infamous" and believe that infamous is when a person becomes more than just famous and reckon El Guapo is a big movie star in Mexico). After breaking into the studio to retrieve their costumes, the Amigos head for Mexico.

At a cantina near Santa Poco, a German pilot inquires about El Guapo and demands respect for his friends who will arrive soon. The German is a fast draw and shoots anyone who aims a gun at him. Stopping at the cantina near Santo Poco, the Amigos are mistaken for associates of a fast-shooting German pilot (Kai Wulff), who is also looking for El Guapo and who arrived just before they did. They mistake the fearful patrons for star-struck fans and perform a cheerful song and dance ("My Little Buttercup"). After they leave, the German's associates arrive and shoot up the cantina when the off-guard patrons mock their fine clothes.

A relieved Carmen picks up the Amigos and takes them to the village, where they are put up in the best house in town and treated very well. The next morning, when three of El Guapo's men come to raid the village, the Amigos do a Hollywood-style stunt show that leaves them very confused. The bandits ride off, making everyone think that the Amigos have defeated the enemy. The village throws a boisterous celebration for the Amigos and their (supposed) victory. In reality, the men inform El Guapo of what has happened, and he decides to return in force the next day and kill the Amigos.

The next morning, El Guapo and his gang come to Santo Poco and call out the Amigos. But they think it's another show. After Lucky is shot, they realize they are confronting real bandits and beg for mercy. The Amigos confess that they have only been acting and are too scared to confront him after Lucky gets shot in the arm. El Guapo allows his men to loot the village and kidnaps Carmen, and the Amigos leave Santo Poco in disgrace. With nothing waiting for them back home, Ned persuades Lucky and Dusty to become real-life heroes and go after El Guapo.

Their first attempt to find his hideout fails. They try summoning a magical swordsman to locate El Guapo, but Dusty botches the ritual and shoots the swordsman. Then they spot a cargo plane and follow it to him. The plane is flown by the German, who has brought a shipment of rifles for the gang with his associates' help. Preparations are underway for El Guapo's 40th birthday party, and he plans to make Carmen hi bride. The Amigos try to sneak into the hideout, with mixed results. Lucky is captured and chained up in a dungeon, Dusty crashes through a window and into Carmen's room, and Ned ends up stuck in the pinata.

As Lucky frees himself and Dusty sneaks out only to be caught, Ned falls loose and is also captured. The German, having idolized Ned's quick-draw and gun-spinning pistol skills since childhood, challenges him to a shootout. Ned wins, killing the German, and Lucky holds El Guapo at gunpoint long enough for Carmen and the Amigos to escape - first on horseback, then in the German's plane.

Returning to Santo Poco with El Guapo's entire army in pursuit, they rally the villagers to stand up for themselves and plan a defense. The bandits arrive in the seemingly empty village, only to find themselves suddenly being shot at by Amigos from all sides and falling into hidden water-filled trenches dug by the villagers. Eventually all of El Guapo's men either desert him or die in the gunfire, and he takes a fatal wound as well. As he lies dying, the villagers - all armed and wearing replicas of the Amigos' costumes - step out to confront him. El Guapo congratulates them on this plan, then shoots Lucky in the foot and dies.

The villagers offer to give the Amigos all the money they have, but the Amigos refuse it, saying (as in their movies) that seeing justice done is enough of a reward for them. They then ride off into the sunset, ready to continue being real heroes.