To obtain the Sorcerer Trait on a particular sim, you need to go into Build Mode and place a Suspicious Lump of Clay anywhere on the Lot (this is a variation on the Lump of Clay added through the mod).
The Suspicious Lump of Clay has one interaction on it: Investigate Object. The tooltip says the consequences of investigating may be permanent, but with 2.0 and beyond, you can remove the trait using the Suspicious Lump of Clay.
When the interaction completes, your sim will now have a new hidden trait and a Spells menu with a toggle "Show/Hide Magical Energy Tingles," even if they are as young as Toddler. Toddler and older can get the trait, but Toddlers and Child sims have a different (and very limited) experience. Teen or older gets access to all the main features of the trait.
Now that you have the trait, clicking on your Sim will reveal a new menu called Spells. Under Spells, you'll see a menu called "Meditate on the Spirit of Llamadeus..." Under this menu, you'll see three interactions: Ritual of Digestive Control, Ritual of Runner's Vigor, and Ritual of Forced Isolation. Hovering over each tells you what it gives you, uniquely.
You can only complete one Ritual and it will define what flavor of Sorcerer you end up with, in terms of Needs. Every type gets two new Needs called Magical Connection and Alignment. These two Needs replace two of the six default Needs. The rituals and traits are as follows:
- Ritual of Digestive Control gives a trait called Iron Insides. With Iron Insides, Bladder and Hunger are replaced by Magical Connection and Alignment.
- Ritual of Runner's Vigor gives a trait called Never Bedheader. With Never Bedheader, Hygiene and Energy are replaced by Magical Connection and Alignment. [To avoid some weird bugs, Hygiene decays very slowly instead of being locked at max. I may explore an alternative to this in the future.]
- Ritual of Forced Isolation gives a trait called Sociolite. With Sociolite, Fun and Social are replaced by Magical Connection and Alignment.
Once you've chosen a Ritual and completed it, your sim can begin being a Sorcerer!