A team goes through a number of games in various phases to try to steal some of Pere Fouras's treasure from the Treasure Room of the fort.
There's a large number of characters, although not all appear in each episode:
Olivier Minne: The show's host, accompanies the team, talks through game rules.
Pere Fouras: Isn't exactly played as a villain, more as a mischevious game master-y type. Rarely meets the players directly, but will often communicate with them for riddle challenges.
Passe-Partout: Accompanies the team, keeps score.
Passe-Muraille: Acts as go-between between Pere Fouras and the team, passing on instructions about the next game. Likes dressing up.
Felindra: Trains the tigers that guard the treasure room.
The Family Boo: Mister Boo and Lady Boo participate in games where the team needs a specific opposition. Mister Boo also acts as jailer
Patrice Laffont: The original host of the show, brought back for the thirtieth anniversary for a 'time machine' game featuring classic tests from the show's past.
Magik: The fort's genie, hosts a game based around fakir trials.
MegaGaf (No, not that Gaf!): Played by Vincent La
Gaf (you see?); a superhero convinced that Pere Fouras is a supervillain, constantly trying to assault the fort.
Rouge: Sister to Blanche, she trains combatants to test the teams
The Children of the Fort: Rouge's champions, children skilled in martial arts and gymnastics.
Blanche: Sister to Rouge, she sits in judgement
Chef Willy Rovelli: The Fort's chef. Not a particularly good cook.
The Masters of Time: Pere Fouras's head lieutenants, who play small-scale duels with the contestants.
There's a lot of phases:
1: Quest for Keys
The team has 50 minutes to collect nine keys from various games around the fort. This is rarely achieved, but the more they get, the better later on. The games are short timed challenges, explained immediately beforehand, you can generally deduce what's going on. Any player who runs out of time in a challenge room will be imprisoned; Mister Boo will take them to the Fort's cell. Some challenges are played by teams of two. Outdoor challenges are often accompanied by a cluebox; rather than having to retrieve a physical key they're trying to get to a point where they can read a four-digit code, allowing the team to open the box and retrieve the key. At least one challenge is generally a riddle where Pere Fouras tasks the contestants with answering while dealing with... distractions. At some point in proceedings Rouge will issue a challenge to the players, at which point time stops briefly while they proceed to the Cage.
1b: The Cage
An opportunity to win up to three keys in one-on-one challenges against Rouge's champions. These challenges tend to be physical or gymnastic in nature.
2: Judgement
After the fifty minutes are up, the team proceeds to the entrance to the Chamber of Judgement. They have to pick one player to sacrifice to Blanche for each key they're short of the nine required. Each player goes into the chamber and is invited to pick either a chance or skill game to free themselves; skill games give you three distinct chances to complete a ball-based task, chance games invite you to pick a 50/50 outcome from a random event. Failing results in those players being taken to the cells; success returns them to the group. Also at this point any player imprisoned in the first part is also brought before Blanche for judgement, and the same criteria takes place; winning a task releases the player, failing sends them back to the cell.
This season this phase concludes with a final test; a member is invited to sacrifice themselves to... something, they don't quite know what, but "fortune favours the brave"...
Interlude: Chamber of Adventures / Willymix
Now the game gets a bit more serious, we move on to the Adventures. The team is shown the schedule of adventures for this week, and has a brief discussion about which they'd like to avoid... generally all of them, because the Adventures are largely fear-based challenges. They have an opportunity to win a joker to allow one player to pass on an adventure to be replaced by another if the person sacrificed earlier beats Willymix, where the game gets a wee bit Nickelodeon as Chef Willy places the contestant in his automated cooking device (i.e. elaborate gunge tank) and gives them an eight-question quiz on the history of the show. Four correct answers wins the joker, incorrect answers mean... well, you know.
3: Quest for Clues
The team have keys to the treasure room, but they need the password to release the treasure, and so they're invited to play fear-based challenges to get capsules containing clue words. Six such challenges, usually with at least one height-based challenge and at least one trip to Chez Willy, where Chef Willy invites the team - together - to enjoy one of his fine meals. If the team won a joker earlier they can choose to replace the contestant lined up for the current challenge, but can't choose who to replace them
with...
In the rare event that the team managed to secure all nine keys in the time limit in the Quest for Keys, they get one extra Adventure here for a chance of a bonus clue word.
4. Quest for Time
Now the players have a number of clue words, and so the final thing they're playing for is the amount of time the treasure room gate remains open. They start with 3:00, but this can change!
4a: The Great Escape
If any player is still imprisoned at this point, they have 2:30 to escape the cell; there's a small escape room portion in the cell itself, then a course to complete, ending up in a trapdoor directly under the team's feet. When the escapee pulls the lever next to the team, the time stopped. Any time they took
beyond 2:30 is deducted from their treasure room time.
4b: The Council
Pere Fouras calls the Masters of Time to host the council; the one time he directly meets the players. He calls four players from the team in one-at-a-time to play duels against the Masters, generally very simple games (often with an elaborate staging - a shaky-hand game across the body of a giant dragon which spits sparks if you hit the side, for instance!). Each duel won awards +15 seconds to the team
5: The Treasure Room
The final segment. The team insert their nine keys, and get ready with the clue containers. When Olivier starts the clock, the treasure room gate opens, and they can start opening the clues. If they feel they need more clues, they can sacrifice a player to get an extra one. When they have it, they spell out the word on the floor of the Treasure Room, and if they're correct, the coins are released! In whatever time they have remaining they gather what coins they can and carry them out to the bucket; after the time is up the contents are placed on a scale and weighed, and that's the prize money going to their charity.
Sometimes: Toujours plus Fort!
This season - for the anniversary - they're quite frequently having a lengthy post-game chat with the contestants, interspersed with a few extra challenges for bonus money and segments on the history of the show. It's not on every week.