Right behind "pick up everything that isn't nailed down" on the list of rules to live by for players of adventure games. First used surrounding the classic Infocom and Scott Adams1 text adventures, this phrase still is in use today among followers of high poly count 3D adventure games.

In some adventure games, unlike the popular Myst series2, there are numerous ways to tread down dead ends from which there is no recovery. Saving early and often (and never overwriting old saved games!) allows the player to return to a state before the fatal decision.

Examples of erroneous tasks for which the consequences are not known until much later in the game:

1 Not to be confused with the Scott Adams of Dilbert fame

2 That doesn't stop those of us who are addicted to "Save Early, Save Often" from doing so in these games, of course.

Spoilers abound below this line

3 The pile of leaves is a trap. You'll notice a message written in the sand next to the leaves indicating that you should not interfere. After you visit the Olde Magick Shoppe and return to the site of the pile of leaves, the leaves will have disappeared. Instead there is a hole filled partially with water. At the bottom of the hole is a stranded Platypus. You must rescue the Platypus (who happens to be royalty on a nearby island) in order to complete the game. If you disturb the pile of leaves early in the game, the trap doesn't work and you have to start over from the beginning.

4 The translucent rooms have hallways between them that can be altered by you and your trusty magic pencil, eraser, and map. When you connect the lines to the isolated room on the map, you allow the Evil Presence to roam freely between the translucent rooms. You must herd it into a room with no goodies and then isolate it again so that you may go into the maze and obtain the powerful magic items within. If you allow a connection between the rest of the castle and the translucent rooms while the evil presence is loose -- it may get into the castle and return to its original form -- a form which it may use to better destroy you.

5 You obtain a number of items early in this game which have no immediate purpose. Many you will try to exchange for (prematurely interrupted) sex with a number of other non-player characters. At some point, you will be bargaining through the stage entrance for a night of passion with a can-can dancer. If you give her the wrong item(s) (and she'll take just about anything in your posession), you may not have them later in the game when you need them. Showering without soap will not make you clean -- and you won't understand the importance of being clean until after you complete your shower.

6 Adjusting your gun sights is one of the tasks supposed to make Police Quest 2 more like "being a real cop." It takes a while to figure out the first time you are in the station (you must obtain your sidearm, suitable ammunition, find the range, and use it without destroying your eyes or ears) but adjusting your sights means that when you actually need your weapon you will be able to fire it smartly. You will encounter serial murderer Jesse Bains near the river and exchange gunfire. If you don't have well-adjusted sights, you will miss him wildly and he will have no incentive to stop firing. Therefore, you will be hit and you will die. It is important to note the not-so-subtle hint later in the game where, when making the break-in at the motel, you "slam your gun-hand against the wall" dodging the automated shotgun blast. Hurting your hand pretty well messes up any consistency you have built up over time; you must re-adjust your sights to compensate... or you won't be able to shoot Mr. Bains the next time you encounter him.