Adventure games are often called "interactive fiction". You play a character in a mythical world, receiving information through typewritten text and giving commands to your character through short typewritten sentences. Not quite Dungeons and Dragons, but all sorts of different worlds have been created. The first ones were just big cave systems, where you wandered looking for treasure. New ones have complex plots, and might involve overthrowing the government, stopping an earthquake, or even going to a university. So for instance, you explore by being placed in a world and reading YOU ARE STANDING IN AN OPEN CLEARING IN FRONT OF A SMALL WHITE HOUSE. THERE IS A MAIL BOX HERE. A PATH TO THE NORTH LEADS AROUND TO THE REAR OF THE HOUSE, WHEREAS TO THE SOUTH YOU CAN SEE A PATH TO A LAKE. Then you decide what to do. A common thing is to try to get more information, for example by examining the house > EXAMINE HOUSE THE WHITE HOUSE IS VERY PRETTY. THE FRONT DOOR TO THE HOUSE IS CLOSED. > LOOK IN MAIL BOX YOU FIND A POSTCARD, WHICH YOU TAKE. > READ POSTCARD THE POSTCARD IS A TOUCHING REMINDER FROM YOUR FRIEND IN ITALY TO FEED THE CAT. > INVENTORY YOU HAVE A POSTCARD AND A BOTTLE OF SHOE GOO. In most of the games the plot and text are designed to be amusing and/or interesting, but the basic conflict, the basic challenge, comes through puzzles in the game. So, for instance, you may be placed in a small world that you can explore, but there may be a locked door in it. The "puzzle" is to find the key to unlock the door and get into the bigger world. An easy puzzle might put the key under a doormat in front of the door. Looking under the doormat would reveal the key. A hard puzzle would put the key on a stone platform. Taking the key would cause a flight of arrows to hit you. To solve the puzzle, you would first have to place a small rock on the platform to fool the arrow mechanism. Presumably the small rock would be made prominently available, such as THERE IS A SMALL ROCK HERE. Many puzzles involve realizing that objects have multiple purposes. If your hands get cold, realize that your lamp is not only a source of light, but also a source of warmth. Other puzzles involve figuring out what sort of fiendish sense of humor the authors have. This game, sadly, is rife with such puzzles. When you have solved a particularly important puzzle, a game may tell you that it has increased your score. GC contains many, many puzzles, some easy, some very difficult. There are lots of objects, so it won't be obvious, for instance, what device might help with what puzzle. The existence of some puzzles won't even be obvious- you may have to figure out that waking the sleeping king is a puzzle, or alternatively that it isn't and that he is just there to let you know a king exists. And, to make the game more difficult, there are red herrings. Just because there is an umbrella in the game doesn't mean it serves a purpose. And just because someone says "Go North, young man" doesn't mean you gain by following the advice- though it might be worth keeping the advice in mind. You can't perform arbitrary actions, as the game is actually quite dumb. Essentially, you can't do something unusual enough that we, the designers, didn't anticipate it. So that means that most everything you do in the game should be a fairly obvious or natural action. If you have a gun, you shoot it. Most likely you don't disassemble it, unless the necessity of the disassembly of the gun is made painfully obvious to you. Consequently, the parser is not complicated- there is no point in having a sophisticated linguistic interface to a dumb program. You can essentially type single verb commands, such as > JUMP or apply a transitive verb to a direct object, like > TAKE THE CUP > ATTACK THE SNAKE > THROW THE BALL > LOOK UNDER THE RUG > LOOK BEHIND THE BOOKCASE > CLIMB STAIRCASE > ENTER THE WINDOW occasionally you can also apply a verb to a direct and an indirect object > SHOOT GUN AT THIEF > BREAK THE VASE WITH STICK > HIT THE OBLONG BALL WITH BAT > ASK WIZARD FOR WAND > DROP FRED IN THE LAKE there are a few specialized commands to, such as > SAY "HELLO" > N > UP > IN > EXAMINE,X > LOOK,L > INVENTORY,I > AGAIN,G > WAIT,Z > UNDO > SAVE The parser generally allows you to specify objects with or without adjectives, first names, etc. > TAKE BOOK > TAKE THE RED BOOK > TAKE THE SMALL RED BOOK If you can't figure out how to phrase something, almost certainly you aren't supposed to be doing it in the first place. For instance, if you want to "REACH HAND INTO BOTTOM OF POT AND STIR CUCUMBERS", don't bother. If that were necessary, there would be a ladle and the command would be > STIR POT or > STIR POT WITH LADLE or > STIR CUCUMBERS or > STIR CUCUMBERS WITH LADLE and most likely all four things would have worked. The game will describe where you are to you, and most interesting things about the world. Sometimes you will need to examine the world in more detail, by using EXAMINE (almost always X everything), or by looking places the game implies but doesn't declare. Like behind the woodpile, or under the carpet, or in the pot. Most important objects are declared explicitly to make it very plain they are special, such as THERE IS AN ANCHOVY HERE. or THE GRAND SULTAN OF ZANZIBAR WALKS IN. But other times the objects will be described in an offhand way in the text- THE LUSH GRASS MAKES THIS PART OF THE FIELD SEEM EXTRA SPECIAL. > X GRASS IT IS LUSH, AND QUITE LIKELY EDIBLE. > EAT GRASS MMM. YOU TURN INTO A COW. Very rarely there will be an important aspect of the game that isn't mentioned at all. For instance, the game might not usually tell you what the sky looks like, but when you do a rain dance, it tells you THE SKY TURNS DARK. If you find something described in the text that you can't refer to, or the game says > I DON'T KNOW THE WORD "FILIGREE" that almost assuredly means that wherever filigree was mentioned, it was as a decoration to make the game seem more vivid, and is completely unimportant. Usually, the first time you walk into a room you receive a detailed description of the room. Subsequent times you just get the important stuff, such as who else is in the room. You can always get the full spiel again with > LOOK The world in most adventure games is really just a big directed graph. You are at a node, and you can get to another node by typing "NORTH" or "SOUTH", "IN" or "OUT", or sometimes SAY "ABRACADABRA". You can map the world out on paper to make it easier for you to visualize where you are, and where other things are. It is traditional for games to have a maze, which might be a part of the world where the arcs don't really obey the laws of geometry, or where the game doesn't give you enough information to tell where you are. It used to be that mazes were hard to solve and had to be mapped by luck and extreme patience. Now they're hellishly hideous, but almost always there's a better way to find your way through them, like by turning off your lamp and looking for glow-in-the-dark arrows (presumably something would give you a hint about this) or by finding and bribing a guard to guide you.