Cheapest priced copy (Ultimate Masters): $0.39 at Card Kingdom, near mint, their price list as of .
Raid Bombardment 
Enchantment · Uncommon · Wilds of Eldraine: Enchanting Tales · #47
Whenever a creature you control with power 2 or less attacks, this enchantment deals 1 damage to the player or planeswalker that creature is attacking.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
3 printings · $0.39 to $2.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Rise of the Eldrazi | 161 | Common | $0.49 | $2.49 |
| Ultimate Masters | 142 | Common | $0.39 | $0.79 |
| Wilds of Eldraine: Enchanting Tales | 47 | Uncommon | $0.39 | $0.49 |
5 rulings from Wizards of the Coast
- 7 December 2018A creature with 0 power can attack, as long as it doesn't also have defender.
- 7 December 2018If the attacking creature leaves the battlefield before Raid Bombardment's triggered ability resolves, Raid Bombardment deals 1 damage to the player or planeswalker that creature was attacking before it left the battlefield.
- 7 December 2018The power of the attacking creature is checked only when the ability triggers. Once it triggers, Raid Bombardment will deal 1 damage to the appropriate player or planeswalker even if the creature's power changes before the ability resolves.
- 7 December 2018If you attack with multiple creatures with power 2 or less, Raid Bombardment's ability triggers for each of them separately.
- 1 September 2023Raid Bombardment's ability won't do anything when a creature you control with power 2 or less attacks a battle.