Cheapest priced copy (Strixhaven: School of Mages): $0.35 at Card Kingdom, near mint, their price list as of .
Fractal Summoning 
Sorcery — Lesson · Common · Strixhaven: School of Mages · #187
Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Strixhaven: School of Mages | 187 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 16 April 2021Lesson is a spell subtype found on some instant and sorcery cards in the Strixhaven set. The Lesson subtype has no special rules associated with it.
- 16 April 2021Although you may want to include Lessons in your sideboard if you’re playing with cards that instruct you to learn, Lesson cards can be included in your main deck like other instant or sorcery cards.