Can PCs learn skills, tool proficiencies, or spells from other players' characters in the game? In our game the rogue and ranger spend a lot of time scouting and working together. The rogue wanted to know if she could learn some of the ranger's skills.
Since you can learn new skills in town with a certain amount of time spent for training it didn't seem too unreasonable. That got us thinking about what else players can learn from each other, like can a wizard learn arcane spells from a bard, or can tool proficiencies be taught while campaigning together?