I have a bunch of third-party supplements adding lots of new spells to 5e and I really want to get more use out of them. How can I add new spells to a campaign in a fun and satisfying way? I want to do something more interesting than just giving my players more sources to choose their PC's spells from. Really, I'd like to make discovering and using new spells the center of the campaign. Here are some ideas I had, what do you think? These concepts all require houserules or change some of the core assumptions of 5e, so I'd need to be clear in session zero on what the campaign was going to be about and make sure all the players were enthusiastic about playing under these conditions. For instance, RAW only wizards can learn new spells outside of gaining a new level, but I'd extend that to everyone.
- Some external threat is making it impossible to cast certain spells, forcing the party to seek out new replacement spells while investigating the cause of the spell outage.
- A campaign as a riff on Pokemon, where the party's goal is to "learn 'em all" by filling out a spellbook with every possible spell.
- A curse of some kind keeps PCs from being able to choose the spells they prepare each day. Instead, the PCs get a random set of spells that they may not have previously known. (This might also work as a subclass, and has probably already been written up as one. The trick would be determining what perks to give the subclass in exchange for losing the ability to select the spells they have available.)