Cheapest priced copy (Gatecrash): $0.35 at Card Kingdom, near mint, their price list as of .
Guildscorn Ward 
Enchantment — Aura · Common · Gatecrash · #15
Enchant creature
Enchanted creature has protection from multicolored.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Gatecrash | 15 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 24 January 2013Hybrid spells and permanents in the Return to Ravnica block are multicolored, even if you cast them with one color of mana.
- 24 January 2013The enchanted creature can’t be enchanted or equipped by multicolored Auras and Equipment, it can’t be blocked by multicolored creatures, it can’t be targeted by multicolored spells or abilities from multicolored sources, and all damage dealt to it by multicolored sources is prevented.