Cheapest priced copy (The List): $0.35 at Card Kingdom, near mint, their price list as of .
Flux 
Sorcery · Common · Weatherlight · #39
Each player discards any number of cards, then draws that many cards.
Draw a card.
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| The List | POR-55 | Uncommon | $0.35 | — |
| Portal | 55 | Uncommon | $0.39 | — |
| Weatherlight | 39 | Common | $0.49 | — |
2 rulings from Wizards of the Coast
- 4 October 2004The discard is forced even though you choose how many to discard.
- 1 April 2008Each player chooses how many cards they would like to discard. That number may be 0.