In the comments on one of the Thief skills, Scott Anderson and I talked a little bit about training to get additional abilities not covered by your class. It’s worth addressing in its own post.
As I said in the comments, I allow characters to pick up additional abilities in two way… except really, it’s three ways. OK, maybe two and a half.
- At Character Generation, by purchasing a tool needed for that ability. Thus, a character who begins the game with a set of thief tools can have mundane lockpicking ability. This does not apply to supernatural abilities, and it can’t be used after character creation. This is really shorthand for…
- Through Backgrounds. This is nothing like the 5e backgrounds, but is an adaptation of the AD&D Secondary Skills system that I’ve written about before. At character creation, or after years of downtime and training, a character can be assigned one or more mundane professions, like blacksmith, baker, or sailor. This does not give any bonus, but it removes any penalty for being untrained. Further, if any skill requires a minimum ability score, the number of years of experience in a background can be used as a substitute.
- Through Research and Training. I adapt the magical research rules to calculate training costs and time, which I’ve described in a couple places, including this post: Bribe, Craft, Train. Short version: learning a spell costs the same as researching a new spell, with the same chance of success. Mundane skills cost one-tenth that, and are usually treated as 1st level spells, although the level can be adjusted.
After acquiring a new ability through training and research, a character essentially has a background with 0 years of experience. The ability can only be improved through time, as for other backgrounds. So, a character that trains as a blacksmith knows the basics, but may still have a chance of botching smithing jobs until they’ve worked as a smith for a year or two.
I try not to set too many minimum training time requirements, other than on-the-fly assignment of levels. Most simple mundane tasks can be trained as if they were 1st level spells. Heavy physical skills might be set as 4th level, so that they require a minimum of one month of training.