An evil magician (who never actually appears in the game) has stolen the Enchanted Chalice and hidden it somewhere in the Kingdom. You have to find it and return it to the Golden Castle. Along the way, you will face three dragons, confusing asymmetric mazes, and a bat that steals your items. Your one-item inventory can include a sword, a bridge (for short-cutting the mazes), one of the keys to the three castles, a magnet (to attract other items, right through walls), the Chalice, a dot (for unlocking an Easter Egg), and, for short periods of time, the bat. The Kingdom consists of the Golden Castle (where you start), a maze leading to the Black Castle, a catacomb leading to the White Castle, and a few other rooms. Inside the Black and White Castles are more mazes and catacombs.
There are three versions of the game, selected with the Game Select switch. Version 1 omits the White Castle, Rhindle the dragon, the bat, and all mazes except the one leading to the Black Castle. Version 2 has everything, but always in the same places. Version 3 puts the objects in random locations. You can also tweak the difficulty with the difficulty switches: left difficulty changes the speed of the dragons' bite, and right difficulty controls whether or not the dragons are afraid of the sword.
The three dragons have different behaviors. Yorgle, the Yellow Dragon, is slow (moving half the speed of the player), and guards the Chalice. He's afraid of the Golden Key. (Don't ask why.) Grundle, the Green Dragon moves at the same speed as Yorgle, and guards the Magnet, the Bridge, the Black Key, and the Chalice. Rhindle, the Red Dragon, is fast (moving at the same speed as the player, or twice as fast as Yorgle or Grundle), and guards the White Key and the Chalice. The Bat flies around the whole kingdom grabbing stuff. He has a one-item inventory too, so he's always exchanging what he has for what he wants, and he's especially interested in what you have. He can even grab your sword and hand you a dragon!
Sprite flicker plays a big part in the game, and is actually mentioned in the manual as a way to get through dead dragons if they're in the way. Sprite flicker is how you reach the Easter Egg; you bring the gray dot from the Black Castle to one of the rooms with a force field wall, and it makes the force field flicker, so you can pass through it into a hidden room that says "Created by Warren Robinett." Atari didn't credit its game developers at the time, so Warren snuck that in.
Adventure was a big hit, selling a million copies. Though it's not considered a true Role-Playing Game, it's an ancestor of every Top-Down View and Three Quarters View RPG and action-adventure game. Word of God is that it was originally intended as an attempt to port Colossal Cave to the Atari 2600.
Adventure provides examples of:
- 100% Completion: Of a sort. Winning is purely binary, but one can get the effect of a 100% run by collecting every item in the game, including the dragons and the bat, and sticking them all in the Golden Castle. This is easiest with Dragon corpses, but it can be done with live ones.
- Three Quarters View: Perspective is pretty weird, similar to The Legend Of Zelda I. It seems to be Top-Down View, but if that's the case, then the castles are lying on their backs, and the dragons are lying on their sides...
- All There in the Manual:
- The plot, as well as the names of the dragons. And it's not entirely accurate or complete. The Green Dragon may have originally been named Grindle but was misspelled as Grundle, and it stuck. The bat would have been named Knubberrub, but this was left out and the bat is just called the Black Bat.
- Likewise, all the area names are in the manual. The blue maze leading to the Black Castle is the Blue Labyrinth, the limited-visibility maze leading to the White Castle is the Catacombs, the maze inside the White Castle is the Red Dungeon, and the maze inside the Black Castle is the Grey Dungeon. And your home castle is the Golden Castle, not the Gold Castle or Yellow Castle.
- Artificial Brilliance: The three dragons are all very well programmed for their time, their AI which switch between either "roaming" or "guarding" depending on what items are, or are not present, and what you do, or do not decide to steal. You can also entice them to flee by bringing the sword with you if the Right Difficulty switch is set to A, and Yorgle will flee the Yellow Key regardless of difficulty settings.
- Blackout Basement: The Catacombs leading to the White Castle and the interior of the Black Castle on difficulty levels 2 and 3. The entire screen is gray except for a yellow circle of light around your character and other sprites.
- Chromatic Arrangement: The dragons (if you substitute yellow for blue). Played straight with Indenture for DOS, where you have four coloured beasts after you.
- Controllable Helplessness:
- You can wiggle around after you've been eaten by a dragon. You can also grab items that happen to be very close to the dragon that's eaten you. Such as... the bat. This allows you to see how the bat flies around and even disrupt his route if you need to make sure he doesn't get to a certain item before you reincarnate.
- You can enter the game selection screen by moving the joystick. There's nothing you can do in the room, however, except move around. The game selection number is an obstacle you can't move through, you can't exit through what looks like an exit at the bottom of the room, and you disappear if you advance the game selection number, though you can then enter the screen again.
- Death Is a Slap on the Wrist: If you get stuck or eaten by a dragon, you can hit Reset and return to the Golden Castle. Everything will be right where you left it, but the dragons will be alive again.
- Depth Perplexion: You're the only one who has to deal with walls. The dragons and the bat go right through them. So do objects when the magnet's on screen.
- Easter Egg: The Trope Maker and Trope Codifier, though not (as is commonly believed) the first ever.
- Empty Room Psych: Several of them. Because the bat moves things around they might not be empty if you return later.
- Excuse Plot: An Evil Sorcerer has stolen the Enchanted Chalice. Find it and return it to your starting point. But it's what you do along the way that's the adventure.
- Fan Sequel: The homebrew Adventure II for the Atari 5200.
- Also Indenture for MS-DOS, a freeware game that's not exactly a sequel but an expansion, adding Game variations 4 and 5, which add a fourth dragon (Disgruntle, a blue dragon that moves faster than Rhindle), several more castles (green and flashing), a second dot (actually a small diamond that opens up left-side walls), a whistle to paralyze the bat, literally hundreds of new rooms (most of them horrific mazes), and a "secret ending" involving four special "tokens". (Game 4 has the objects in predetermined locations, while Game 5 scatters them around randomly, like Games 2 and 3)
- Featureless Protagonist: You play as a small square.
- Flip-Screen Scrolling: with warping that makes the mazes very confusing.
- The Ghost: The evil magician. The manual states that he not only hid the Chalice, he created the dragons and the bat. But he never appears in the game. He was made up by manual writer Steve Harding.
- Heroic Fantasy: In a very simple form. There's a sword-wielding hero, dragons, castles, a villainous magician (sort of) and a quest.
- Hollywood Magnetism: The Magnet can attract any object on a screen except dead dragons and the dot, regardless of proximity. In addition: if multiple objects are on the screen, the Magnet will only attract a single object (with the Keys getting top priority). If you remove the first object attracted from the room the magnet will then begin attracting the next object, and so forth.
- The Hunter Becomes the Hunted: When you find the sword you can turn the tables on Yorgle, Grundle and Rhindle.
- Insistent Terminology: In the manual, all the item and area names are always capitalized and very specific. For example, it's never just "the chalice", but "The Enchanted Chalice".
- Inventory Management Puzzle: Can get pretty tricky with a one item inventory limit. Sometimes it makes a great difference where you grab an item as well - it can be tricky to use your sword when an approaching dragon is on the other side of you.
- It IS possible to bring along two items with a trick - dropping an item pushes it in front of you, just a little farther than an item you can pick up, so you can bring two items along by constantly swapping them as you move forward.
- The Key Is Behind the Lock: On the hardest difficulty, the items are distributed in a kind-of-random manner, which occasionally results in the Golden Key being locked in the Golden Castle.
- Logic Bomb: Easiest way to get rid of the bat? Give him the Golden Key, then drop him inside the Golden Castle, flying upwards and/or sideways, with no other items inside. The Wrap Around walls and ceiling won't let him escape unless he moves downward, and as long as you didn't bring any other items in to distract him, he won't change direction on his own.
- MacGuffin: The Chalice.
- MacGuffin Guardian: When the dragons aren't roaming around looking for you, they're usually guarding their favourite item. If you wait long enough and their favorite item is outside a castle they will eventually find it and guard it.
- The Maze: Four very confusing asymmetrical mazes. Worse, two of them - the Catacombs and the Grey Dungeon - are darkened, only letting you see a small area around your character!
- One-Word Title: Named after the point of the game.
- Our Dragons Are Different: Yorgle, Grundle, and Rhindle generally follow the Western tradition, but they look like ducks, lack wings and just inexplicably slide around the screen, and don't breathe fire.
- Pacifist Run: Probably the first game where this was possible. In fact setting the difficulty so that the dragons are afraid of the sword can make it very difficult to kill any of them.
- Palette Swap: The castles, keys, and dragons.
- Rule of Three: Three castles, three keys, and three dragons.
- Safe Zone Hope Spot: The Golden Castle (when unlocked) can be a sanctuary when you can't shake off the pursuing dragons. Though due to the unpredictable nature of the game's mode 3, one of the dragons may already be in there.
- Soft Reset: Used as an infinite lives feature. All the objects will remain where they were, but the dragons will be alive again.
- Sliding Scale of Linearity vs. Openness: Quite possibly the first open sandbox game. Depending on the mode, the world's items and enemies spawn randomly as well, so while your goal remains the same, how you achieve it is another question altogether.
- Spell My Name with an "S": The yellow dragon is called both Yorgle and Yorkle in the manual, though the latter only appears once and may be a typo.
- Spiritual Successor: Superman was programmed after but released before Adventure, so you can interpret either one as the other's successor.
- Super-Persistent Predator: Rhindle the red dragon can be this when he's after you, especially if he spawns right outside the Golden Castle in mode 3, with you having no means to fight back or hide.
- Swallowed Whole: What happens to you if a dragon catches you. You can do nothing except wriggle, and are forced to reset.
- Amusingly, if another dragon shows up after you have been swallowed it will eat you while you are in the belly of the first dragon. If the third shows up it will eat you as well, from the belly of the second dragon. Since the dragons can pass through each other without harm they can apparently all eat you at the same time too.
- Units Not to Scale: Everything except the dot and the keys is bigger than you are, including the sword, chalice, magnet, and bat.
- Unwinnable by Mistake: The bridge can get you stuck in walls or above a castle. Hit the Reset button. This is even mentioned in the manual. Also, the random placement of objects in game 3 sometimes places the Golden Key inside the locked Golden Castle, with no way to get to it.
- Unless you get lucky with the bat picking up said key.
- Or the bat can drop critical items where you can't reach them. That's the main reason for the magnet being in the game, if it's not itself inaccessible.
- Video Game Caring Potential: Some players find the duck-dragons cute and avoid killing them.
- Wide Open Sandbox: Possibly the Trope Maker. Starting from the Golden Castle, you can either go left towards the Black Castle or right towards the Catacombs and the White Castle. The game is about exploring the world, finding out what's where, and then figuring out what to do.
- A Winner Is You: The screen flashes.