Common Cause
Mana cost
Mana value3TypeEnchantment
Color identity
White
RarityRare
SetMercadian Masques (MMQ)
ArtistJohn Matson
Price€0.42 · foil €5.42 · $0.37
Common Cause 

Enchantment
Nonartifact creatures get +2/+2 as long as they all share a color.
Mercadia City's troops are at their best when they have no enemy to fight.
Legality
CommanderLegalStandardNot legalPioneerNot legalModernNot legalLegacyLegalVintageLegalPauperNot legalBrawlNot legalOathbreakerLegalHistoricNot legalTimelessNot legalPenny DreadfulNot legal
Rulings
2004-10-04
It really does mean “all creatures”, including your opponent’s.
2004-10-04
The ability gives +2/+2 to all creatures which are not artifact creatures, as long as every one of those creatures is of the same color. They can have additional colors beyond the one they share, but they all have to share one color. If any creature is not of the shared color, the bonus is lost.