Plot

Asterix and Obelix are tasked by Julius Caesar with accomplishing twelve impossible labors to determine the fate of their indomitable Gaulish village.

When Julius Cesar fears, that he will probably never be able to defeat the gaulic village of Asterix and his friends, he has the idea of offering the Gauls a deal: if they are able to solve twelve tasks that he selected, he will hand over the Roman empire to them. If not, they have to submit.—Michael Zink

After a group of legionaries is once again beaten up by the Gauls, they imagine: "With such huge strength, they can't be human... they must be gods". Julius Caesar is informed and laughs. He makes a decision with his council and goes to Armorica, to speak with Vitalstatistix. He gives the Gauls a series of 12 tasks, inspired by Hercules (but new ones, since the 12 Labors are outdated). Vitalstatistix assembles their best warriors, Asterix and Obelix, to do the job. The Roman Caius Tiddlus is sent along with them to guide them and check they complete each task. The Twelve Tasks

1 Run faster than Asbestos, champion of the Olympic Games. Asterix, helped by the magic potion, follows Asbestos until he runs so fast (because Asterix keeps taking breaks and STILL is on his tail) he becomes a rocket and exceeds the speed of sound, before hitting an apple tree. His nose swells up like a balloon and Obelix comments on how Gaulish it looks.

2 Throw a javelin farther than Verses, the Persian. Verses' javelin hits North America (still only inhabited by Indians, including another Goscinny-Uderzo character, Oumpah-pah), but Obelix's javelin somehow enters a stable orbit and ends up pursuing Verses around the world, including through the Native American village.

3 Beat Cilindric, the German. Cilindric turns out to be an unexpectedly diminutive man wearing a Judo Gi - but he quickly beats Obelix with a "fighting technique he learned in a distant land". Asterix defeats Cilindric by tricking him into giving a lesson and asking for demonstrations that eventually end up with Cilindric's own arms and legs tied in knots.

4 Cross a lake. The problem being that in the middle of the lake is the "Isle of Pleasure", a paradise inhabited by beautiful Sirens. Both Asterix and Obelix are enchanted and drawn to the island, where they meet the Sirens and spent ages enjoying the pleasures, but Obelix comes to his senses quickly after discovering that there are no wild boars on the island, just nectar and ambrosia, has an incandescent argument with the Sirens, and storms off declaring that they can't call it the Isle of Pleasure if they don't serve wild boars, calling Asterix to follow him.

5 Survive the hypnotic gaze of Iris, the Egyptian. Iris uses hypnosis to make his clients believe they are animals. He tries to make Asterix act to the phrase, "I am a wild boar", but when Asterix constantly breaks his concentration by not paying attention and saying "You are a wild boar" instead, Iris gets horribly confused and ends up hypnotizing himself and bolting out of the building on all fours.

6 Finish a meal by Calorofix, the Belgian. The chef is famous for cooking gigantic meals for the Titans - the task was to eat one of his massive three-course meals "down to the last crumb". Obelix devours a boar with fries, a flock of geese, several sheep, an omelet made with eight dozen eggs, a whole school of fish, an ox, a cow and calf ("because to separate Ze family...Zat would not be right!"), a huge mound of caviar (with a single piece of toast), a camel, ("and before we start on the main course") an elephant stuffed with olives. Later on, the chef leaves the kitchen crying as everything in his kitchen was eaten, but a slightly disappointed Obelix believes that the huge meals were only the starters.

7 Survive the Cave of the Beast. In a distinctly abstract sequence of the film, the pair must enter a cave that no-one has ever emerged from alive - even Tiddlus has no idea what lurks within it. They encounter, among other sights, a skeletal hand that directs them, tennis played with a skull, bats, and a subway (on the Paris Metro station Alesia), before meeting the Beast. The lights suddenly go dark, and the Beast is not shown on-screen. After they leave the cave, Tiddlus asks out of curiosity what the Beast was actually like - Obelix happily replies that it was "very tasty".

8 Find Permit A 38 in "The Place That Sends You Mad". A mind-numbing multi-storied building founded on bureaucracy and staffed by clinically unhelpful people who direct all their clients to other similarly unhelpful people elsewhere in the building, which is also full of confusing corridors and steep stairs. They find a plan of the building, but still feel confused. Obelix goes nearly insane after some time, but Asterix eventually beats them at their own game by asking for an imaginary permit, A 39 in a corridor that nobody knows about, B 65, making the staff victims of their own stubbornness and sending the place into disarray. Eventually Asterix is given Permit A 38 just to make him leave and stop causing trouble, while the person who gives them this goes insane.

9 Cross a ravine on an invisible tightrope, over a river full of crocodiles. Eventually the heroic duo decides to give up on the rope and go the easy way round, jumping off and fighting the crocodiles, leaving the bemused creatures dangling on the invisible wire.

10 Climb a mountain and answer the Old Man's riddle. After a tough climb of the snowbound peak, the Old Man of the Mountain's challenge is to determine, with eyes blindfolded, which pile of laundry was washed with Olympus, "the detergent of the gods". Asterix performs this task easily in a parody of washing detergent advertisements. This last actually impress the Olympian gods themselves, with Aphrodite even suggests to literally grant Godhood to the Gauls, but Zeus refuses to do so as they don't need of another hedonistic god like Dionysus.

11 Spend a night on the haunted plains. The plain, haunted by the ghosts of fallen Roman soldiers, is not an easy place to sleep. Obelix tries to fight them but cannot harm ghosts. Asterix is woken by the commotion and finally snaps and makes an angry rant about all the trouble he has gone through and he is still not allowed some sleep. The ghosts flee when they realize that the Gauls are not afraid of them.

12 Survive the Circus Maximus. When the pair wakes up after a night on the plains, they find themselves in Rome, ("either that or these Romans have learned to build very fast") with their fellow villagers, who have been brought to fight in the Colosseum. After the gladiators are beaten (with the help of Getafix's potion, of course) the animals are sent in, and the Gauls turn the Circus Maximus into a modern-day circus.

After the Gauls succeed in every task, Caesar agrees that they are gods, gives them control of the Roman Empire, and retires to live with Cleopatra in a little house in the country. Caius Tiddlus takes his reward by retiring to the Isle of Pleasure. In the village's celebration, Obelix ask to Asterix if the Gauls really conquered Rome, to which Asterix responds that all what happened to them was a mere cartoon, and that everything is possible on it. Obelix takes advantage of this to Teleport himself and his wild boar meat to the Isle of Pleasure and finally enjoys its place.