This will define how you play your character in its earlier stages, since it dictates what your primary skills are. There are five different types of thieves, each with their own benefits and drawbacks. When you join the guild, your default specialisation is "Prowler" and your primary skills are capped at level 50. After choosing a specialisation, you will be able to advance your primaries up to level 300. You can choose once, so choose wisely.

When you decide you want to specialise, go to Kordane (where you joined the guild) and say you want to specialise. When Kordane asks what you'd like to specialise as, say you want to specialise as a [mugger|cutpurse|prowler|smuggler|safecracker] and he'll make it happen.

The mugger excels in the more violent form of stealing, known as mugging, oddly enough. Tradition demands that instead of stealthily sneaking up on a victim, that they track the victim into a dark alley and give them a serious beating should they refuse to hand over their valuables. Muggers are ideal thieves for the newbie to Discworld, with a flexible range of skills, they find they can cope with most eventualities.

Cutpurses are the more classically educated thief, with a wider range of covert training and a gentleman's style of fighting, they are the closest the thieves guild have to an Assassin. Like the mugger, the cutpurse is another good choice for the newbie to Discworld, with a wide range of covert and a fighting primary.

Some say that this only true thief style, with no real combat training, the prowler excels in covert operations unlike any other. They are the default specialisation of the thieves guild, but also the hardest to start with, which makes them not the choice for the newbie to Discworld.

As their name suggests, smugglers are adept in the art of importing and shifting stolen goods, they are the fences of the thieves guild, with an eye for the value of items. Of course smugglers have to deal with other smugglers so to that end, they're trained with using swords and similar weaponry. Though smugglers are not trained to steal in the guild.

Similar to prowlers, safecrackers are covert specialists. Their game is to sneak into buildings and banks and break open the safes, as the name hints. As with the smugglers, safecrackers are not trained to steal from people or shops and they have no combat abilities to speak of. The 'crack' command is currently disabled, however, safecrackers are still the premiere lockpickers of the MUD.