Almost all of Sierra's point-and-click adventure games have copy protection in their manuals, meaning that those who used illegal copies of the game (or who just plain lost their manual) couldn't progress any further. Most of these copy protection checks occur when starting the game, although a few subvert this trend by placing them about halfway through the game. Some of Sierra's examples:
- Nearly all AGI games had key-disk copy protection that required the original disk to be in the drive to start, even if they were installed to the hard drive. The technical details are here
. Any AGI game that was later placed in a Compilation Re-release has this protection pre-cracked. Note that for some of the VGA games, Sierra actually encouraged you to make copies of the games as backups and use the backups to play. (Some even had instructions on how to do this.) Of course, copying the manuals and guidebooks and other "feelies" are a no-no. - Codename: ICEMAN: The game begins as the main character is on vacation in Tahiti. A nearby volleyball player drowns in the surf and the player must rescue him and perform CPR. Obnoxiously, the game doesn't tell you that it wants you to look in the manual and type off the instructions. However, the introductory walkthrough in the game's manual offers step-by-step instructions, making this section trivial for legitimate first-time players. Also, you can google how to do CPR, the official instructions will work as Sierra's parser always allows lots of synonyms and alternative phrasing.
- Conquests of Camelot: The Search For The Grail also uses this system - you have to look in the manual to solve various riddles throughout the game (but you learn some interesting mythology in the process, albeit myths made up for this game instead of classic myths).
- The Even More Incredible Machine requires you to look into the instruction manual to input a code on a randomly decided page each time you open it. However, during the game's intro, if you click to get past it at just the right time (specifically, when it switches from the second screen back to the first) it will almost always request the code on the first page of the book, requiring you to remember only one code.
- Freddy Pharkas: Frontier Pharmacist requires that you look up recipes in the enclosed "home health manual" and create the prescriptions to solve certain puzzles. Only problem is, when the game was re-released in the Sierra Originals version, only a truncated version of the manual was included in the CD booklet, and one of the required recipes was left out entirely. Oops! Al Lowe, the game creator, has since put the entire doc on his website.
- In Gold Rush!, failing to enter a given word from the manual when prompted by a prospector on the opening screen causes your character to be accused of claim jumping and sentenced to the gallows, immediately kicking you back to the DOS prompt as soon as the rope goes taut.
- The King's Quest series:
- King's Quest III: To Heir Is Human: A very large part of the game revolves around copying lengthy, exact instructions for magical spells from the game manual. Getting the instructions even slightly wrong will end the game. The correct phrasing is to simply type over the exact sentence in the manual, although words like "the" and "a" can be omitted. This is in addition to the disk check at the beginning of the game (that all Sierra games had at the time). Note that doing this copy protection correctly will give you 70 out of 210 possible points, and getting all ingredients to make these copy protection spells easily cover half of the game. This is probably the game with the lowest amount of "game content" compared to "copyprot content"
- King's Quest III is also part of the King's Quest Collection, which has a misprint in the manual, leading to a player most likely getting an (optional) spell wrong until they notice that the misprinted manual decided to rhyme "thither" with "thither" instead of "hither". The VGA remakes with the protection stripped out that allow the player to just work the entire spell with a single command actually make the game vastly easier.
- King's Quest IV: The Perils of Rosella actually has a copy protection joke inserted into the coding. Activating the command box at the start (Ctrl + D) and typing in "Pirate" causes the game to play a small bit clip of "Drunken Sailor" and show a picture of a Pirate, while a text box above reads "Your privileges to this game have been revoked because you are a pirate! 'Yo ho ho!'" See it here! In a straight example, before starting, the game asks you for a certain word in the manual (for example, the fourth word in the second paragraph on page 3).
- King's Quest V: Absence Makes the Heart Go Yonder!: Randomly during the game, you have to cast a spell from Crispin's (dead) wand to get past mundane parts. To cast the spell, you have to look up the symbol on Page X of the manual. Entering the wrong code three times makes the game unwinnable. It was excised in the CD version, which then creates a problem in that you don't remember you have the wand when you need it at the end of the game because it literally has no other use.
- It also made at least one puzzle more confusing. In the floppy disc version, there's a moment where you have to use a spell to improve your aim in order to hook a rope onto a rocky outcrop, rather than the unstable tree next to it (which will immediately break and cause you to fall if you attempt to climb). In the CD version, you don't get asked to cast the spell, and you can choose to rope the outcrop or the tree. If you choose the tree, you get a "Thanks for playing" death message appropriate to having failed the copy protection, even though you never even saw it.
- King's Quest VI: Heir Today, Gone Tomorrow came with a "Guidebook to the Land of the Green Isles", which contains clues needed to ascend the Cliffs of Logic. A wrong answer causes the stone step you stand on to retract, sending Alexander plummeting to his death. Later on the same island is a puzzle where you have to step on floor tiles in an order hinted at by a poem in the guidebook. In a sneakier example, the background on which the manual's text is printed also serves as the map for the catacombs, a maze with several no warning instant death traps.
- The first Laura Bow game (The Colonel's Bequest) requires you to identify a fingerprint to its respective character from a sheet that came with the game; originally, the fingerprints could only be viewed with a special magnifying glass, but this was too unfair (since some of them are fairly similar to begin with), so later printings just did it in black and white.
- Its sequel, The Dagger of Amon Ra, also requires the player to dig information out of the museum guide book that came with the game. However, since in this case the questions all revolve around real Egyptian mythology, they're the kind of thing an obsessive adventure game player would already know. The CD version ditched this.
- In the 1991 Sierra game EcoQuest the player must enter a four digit combination lock, available in the manual, to exit the first room of the game.
- The Leisure Suit Larry series:
- Leisure Suit Larry 1: In the Land of the Lounge Lizards didn't have manual-based copy protection, but age protection - to play the game, you have to answer a question that you'd have to be fairly old to know the answer to. (Presumably.) See for yourself. The VGA remake added actual copy protection questions based on the included Feelies.
- In Leisure Suit Larry 2: Looking for Love (in Several Wrong Places), you have to insert the correct phone number of a woman by inputting it from the manual.
- In Leisure Suit Larry 3: Passionate Patti in Pursuit of the Pulsating Pectorals, there's a promotional code you have to type (which is on a certain page of the magazine the game came with) when presenting your show ticket. In another, you have to know the right locker combination.
- In Leisure Suit Larry 5: Passionate Patti Does a Little Undercover Work, to obtain airline tickets, the player must enter the corresponding symbols from the Aerodork timetable, which was printed in black on red in an attempt to make it uncopyable.
- Leisure Suit Larry 1: In the Land of the Lounge Lizards didn't have manual-based copy protection, but age protection - to play the game, you have to answer a question that you'd have to be fairly old to know the answer to. (Presumably.) See for yourself.
- Police Quest 1: In Pursuit of the Death Angel (VGA): The combination to the main character's locker, which you need to get into to retrieve his uniform, is the score of a football game reported on in the fake newspaper included with the game, and also inputting violation codes while putting an arrested man in jail. The sequel requires the player to identify the last name of the person on a mugshot before playing the game.
- Also, in the first Police Quest, you have to exactly follow "police procedures" from the manual in order to advance in the game, and a large chunk of the gameplay is taken up with following just these procedures. You can pretty much guess these if you're familiar with police movies and/or TV series.
- Quest for Glory II has the map of Shapeir, though luckily you can guess your way to the money changer, and from that point onwards purchase an ingame map.
- Quest for Glory IV: In order to get potions from Dr. Cranium, the player needs to help him remember the "formula" for various elements that go into the potions. Interestingly, the copy protection may not seem to matter since it's "just potions"; however, one of the puzzles required to beat the game requires a potion, meaning that without the manual you can effectively do everything except beat the game.
- Robin Hood: Conquests of the Longbow features a number of puzzles which involve having to consult the papers which came with the game. On the plus side, reading through these provided papers allows you to learn about everything from medieval heraldry, to a secret "hand code" which used letters assigned to different parts of a hand to spell out words, to the purported magical properties of gemstones and trees. There are also dire consequences if you fail.
- Space Quest:
- In the VGA remake of Space Quest 1, to get the cartridge, you have to enter the symbols from the manual corresponding to the term the dying scientist tells you into the library computer. A second copy protection code is used for the coordinates of the Deltaur near the end of the game. Definitely copy protection overkill. The original EGA game doesn't have any manual-based copy protection.
- Space Quest 4 has its copy protection when you first enter the timepod, and you have to use the Space Piston Magazine included with the game to solve the code. The CD version excises it.
- Space Quest 5 has the codes you need to enter to get to the various planets in the manual. Since you need to keep entering the codes throughout the game, it's borderline overkill. And there's no brute forcing here: going to the wrong coordinates wastes time getting there and kills you as soon as you're there.
- Space Quest 6 has the datacorder puzzle, which you need the Popular Janitronics magazine which came with the game to solve. Unfortunately, the 2006 re-released ''Space Quest Collection'' didn't include it.
