Players, especially experienced ones, often want skills or abilities not usually associated with the class that they are playing; they tend to give very good arguments as to why they should.
"Why can't my thief specialize in knives? If he spends all of his time on them, there's no reason he shouldn't be able to become a master!"
One way to address this is with the master point system. Players earn special points, aside from normal experience, given out for exceptional play. The result is two fold - players are satisfied with more customized characters, and the game is enriched as the players work at more involved play!
Be stingy with master points- usually only give one or two per adventure, and make them by no means an automatic thing. Below are some suggested MP costs for various skills and abilities.
- Additional weapon proficiency : 5 MP (charge more for non-warriors) Specialization for non-warrior : 5-7 MP (depending on charcter class and weapon)
- Additional normal proficiency : 5 MP
- Additional unusual profieciency (i.e. warrior learning healing) : 7-10 MP
- Additional extraordinary proficiency (allow a fighter to cast cure light wounds) : 15+ MP
Also, work master point usage into role-playing. For instance, have the above thief spend both of his weapon slots in knives, and if he really wants to be a knife master, he'll work exclusively on his knife skills.
Master points can allow some real flexibility in your campaign. Try 'em out, tinker around with 'em, let me know what you think.
Back to the DM's corner
Thanks to t_catt11 for this contribution!