What is the chance for climbing walls, etc., for non-thieves?
The same chance thieves have of knowing spells or possessing 18/00 strength: none. (I can hear all the fighters saying, “But I can hide in the shadows: Watch this!” Even though the thief abilities have rather unimpressive, mundane names, they are indeed special abilities and can be successfully performed only by someone who has had, and continues to take, training in the thief profession.
In a standard AD&D campaign, there can be no deviation from this rule — and it is a fact of “life” as much as it is a rule of the game. Only thieves can employ abilities described as unique to that class, just as clerics can do only what clerics are described as being capable of. This is obvious, necessary (from a playability standpoint), and logical as well; it takes a great deal of introductory training — specialized training — for a character to attain adventurer status (first level), and continuous review and training in the chosen class(es) if one is to rise in levels. The practice of an adventuring profession is a serious matter, often even a vital one, and each profession demands of its adherents all the interest, energy, and effort they can muster. Any DM who settles for less than this attitude from player characters and still allows them to rise in experience levels as if nothing was amiss is doing the playing group and the game a disservice.
In extraordinary circumstances or for the sake of experimentation, non-thief characters with exceptionally high dexterity might be allowed a chance of successfully performing certain thief-like abilities. This mutates the adventure or campaign, and this fact should be understood by the DM and all the players: what they’re playing isn’t an AD&D game any longer. But it might be interesting if, for instance, any non-thief with a dexterity of at least 16 (and any monsters with the same trait) was given a small chance to use that dexterity similar to the way the ability benefits a thief. In this hypothetical system, the “dexterity benefit” would only apply to those thief abilities that allow bonuses for high dexterity: picking pockets, opening locks, locating/removing traps, moving silently, and hiding in shadows. The percentage chance of success for a non-thief to perform a certain function would be a constant, related only to the character’s dexterity and not to his or her level of experience. The percentage chance for success is the same as the number given as a bonus on Dexterity Table II (Players Handbook, page 12), and success is only possible when a number is given. Thus, a non-thief with 16 dexterity would have a 5% chance of using the opening locks ability, but no other thief-like abilities, and a non-thief would need 18 dexterity to have any chance of locating/removing traps.
In no case could it be justified for non-thieves to have the ability to climb walls using this same reasoning, however. First of all, the ability has no direct relationship to dexterity, or else it would be listed in Dexterity Table II. Second of all, climbing walls is a thief’s bread and butter, his claim to fame, the one thing even a first-level thief can do with a decent chance of success. It stands to reason that a large portion of the thief’s training goes into acquiring this ability in the first place; it isn’t something a fighter-type can pick up over a weekend of rigorous wall-clutching. Climbing walls is like riding a unicycle: It takes forever to learn how, and once you learn the basics you don’t ever get a whole lot better at it than you were when you started. Most people (except for thieves and diehard unicycle riders) will give up after taking a few spills, when it becomes apparent that the bumps aren’t worth the benefits.
