Buying Skills is a rule on B170:
- In order to learn or improve a skill, you must spend character points.
The parameters under which this can be done is later clarified in "Adding and Improving Skills and Techniques" on B272:
- You may only add a skill if you attempted a default roll (see Quick Learning Under Pressure, box) or if you spent most of the adventure around
people who were constantly using the skill.
QLUP is restricted normally for magic since spells lack defaults under the basic magical system:
- Obviously, if a skill has no default, you cannot learn it this way.
Wild Talent or Spell Defaults or Improvised Magic (perk) or Wizardly Dabbler and perhaps Modular Abilities could be ways to learn spells without needing to observe people using the spell (ie having a teacher).
Improvement Through Study (B292) works independently of having free character points to spend (though it would increase the Point Value of a character, similar to B291 Traits Gained in Play) so it's initially unclear whether or not it faces the same restrictions as the preceding section.
B293's purple Finding a Teacher box does mention something peripheral to this:
- You can learn magic without a teacher; use the rules described under Self-Teaching.
While not requiring a teacher doesn't necessarily over-rule the "around people who were constantly using" requirement (example: you just spy on a teacher, but they don't directly teach you) but in directing to the ST rules, only one restriction applies:
- unless the skill description attaches specific conditions that would preclude this
Spells do not actually mention a requirement to observe a teacher, that only applies when spending character points to learn something without time requirements, presumably.
Instead there is this added one:
- You must be able to read and have access to good text-
books.