Cheapest priced copy (Rise of the Eldrazi): $0.35 at Card Kingdom, near mint, their price list as of .
Harmless Assault 
Instant · Common · Rise of the Eldrazi · #24
Prevent all combat damage that would be dealt this turn by attacking creatures.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Rise of the Eldrazi | 24 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 15 June 2010Combat damage dealt by blocking creatures isn’t prevented.