Count the Ways

In 1982, Steve Jackson and Ian Livingstone wrote the first Fighting Fantasy gamebook, The Warlock of Firetop Mountain. To cheat-proof the book, Jackson devised a puzzle based around the various keys you need to find in order to unlock the Warlock's chest and steal all his stuff: Scattered throughout the mountain are six keys, each of which has a number engraved on it. You need to choose three of the keys, add their numbers together, and turn to that number section. Only by finding the correct combination of keys can you win the book.

This sets the template for other authors seeking to ensure their book can only be completed by those playing fairly, but over time their methods get more and more meta. The numbers associated with the items become more subtle than just having them written on for no readily apparent in-universe reason. Or the player can spell out a secret message telling them when to take a nonstandard option, with the number being found via a brainteaser. Jackson himself pioneered reference modifiers, where at certain sections you must add or subtract a given number from that of the section you are currently on in order to take an action not offered by the text; if you don't have the item or knowledge that permits you to use the modifier, you won't even have a clue the option is there!

But there's one other tactic, which basically eliminated the need for items to have numbers associated with them at all.

Alphanumeric codes are debuted by Mark Smith and Jamie Thomson in Sword of the Samurai (published 1986), but are used to answer a riddle:

'Well, man-thing, here is the first riddle:

In marble halls as white as milk,

Lined with a skin as soft as silk,

Within a fountain crystal-clear,

A golden apple doth appear;

No doors are there to this stronghold

Yet thieves break in and steal the gold.'

The Tatsu stares at you in greedy anticipation. When you think you have the answer, take each letter of the answer (don't count words such as 'a' or 'the'), convert it to its corresponding number in the alphabet (i.e. a number from 1 to 26), add them together and turn to that paragraph number.

So, if the answer was 'fire' (which it isn't!), you would turn to 38.

    F    I    R    E

    6 + 9 + 18 + 5 = 38

If the paragraph you turn to is the wrong one (it won't make sense!), turn to 26.

Before this, puzzles and riddles like this gave the reader a choice of three different options, which is obviously much easier to bypass if you don't know the correct answer, although this new possibility wasn't immediately taken up by other authors.

At a crucial point in Slaves of the Abyss (1988), you need to prove you've found and eaten some special herbs to protect you from Bythos:

Check the name of the herbs in the pomander, as marked on your Adventure Sheet. Replace each letter with the corresponding number from the key below. Then add up the numbers that go to make each name. Taking the words in the order you have them written down will give you a three-figure number. Turn to the paragraph corresponding to this number.

P = 0    A = 1    T = 2    E = 1

U = 2    H = 0    M = 3    Q = 4

Although authors Paul Mason and Steve Williams were later responsible for some of the most hair-tearingly frustrating, 100% cheat-proofed books in the series, we haven't quite arrived at the concept's most familiar form yet. We have to wait for another of the series' great innovators, Keith Martin, to turn up before it really takes off.

From Night Dragon (1994), Martin's sixth book for the series, when you reach the titular Dragon the book offers you several different ways of approaching him, one of which is using a pair of Winged Boots:

If you have Winged Boots, you know the name of the man who wore them before you; convert his name into a number using the code A = 1, B = 2, C = 3 ... Z = 26. Add the numbers corresponding to the letters in the name, multiply the total by 3, then turn to that paragraph.

The technique is also used by Jonathan Green (who, I hope doesn't mind me saying, clearly took a lot of inspiration from Keith Martin's work) in many of his later books. But in his adventures for the revived 21st century range, he has a rather interesting idea: What if there's more than one accepted value?

From Night of the Necromancer (2010), an adventure where the player character is a ghost:

Although you have the ability to seize control of another's body to use as your own, the idea of even attempting to possess another living person in order to wear their physical form as you might a suit of armour fills you with unease. If you want to pursue this route to acquire a physical form again, you will need to know where a suitable host can be found, and that means that they have to be somewhere within the castle already. If you know where someone is, and they are alive, then you will also know their name. Convert the first name of the person you want to possess into a number using the code A=1, B=2, C=3 ... Z=26. Add the numbers together, multiply the total by 3 and turn to the paragraph with the same number.

Green includes a specially written section for every name the player can come up with; each possibility has a unique set of statistics and starting equipment, and there is also a section calling you out for attempting to possess your little sister. It's one of the most impressive sequences in the range's history.

(These codes quickly became one of Keith Martin's signature tactics; their appearance in Legend of Zagor is one of the big giveaways that he ghost-wrote it when Ian Livingstone proved unable to do so himself!)