Cheapest priced copy (Saviors of Kamigawa): $0.35 at Card Kingdom, near mint, their price list as of .
Curtain of Light 
Instant · Common · Saviors of Kamigawa · #6
Cast this spell only during combat after blockers are declared.
Target unblocked attacking creature becomes blocked. (This spell works on creatures that can't be blocked.)
Draw a card.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Saviors of Kamigawa | 6 | Common | $0.35 | $0.49 |
4 rulings from Wizards of the Coast
- 1 June 2005An attacking unblocked creature exists from the time the defending player chooses not to block that creature until the combat phase ends. Curtain of Light doesn’t have any legal targets outside of the combat phase.
- 1 June 2005Curtain of Light does trigger bushido abilities.
- 1 June 2005Curtain of Light isn’t particularly effective against creatures with trample. Since the creature with trample has no blocker to assign damage to, all the damage will be assigned to the defending player.
- 20 September 2013If a turn has multiple combat phases, this spell can be cast during any of them as long as it’s after the beginning of that phase’s Declare Blockers Step.