Cheapest priced copy (Magic 2015): $0.35 at Card Kingdom, near mint, their price list as of .
Might Makes Right 
Enchantment · Uncommon · Magic 2015 · #156
At the beginning of combat on your turn, if you control each creature on the battlefield with the greatest power, gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic 2015 | 156 | Uncommon | $0.35 | $0.49 |
5 rulings from Wizards of the Coast
- 18 July 2014Gaining control of a creature doesn’t cause you to gain control of any Auras or Equipment attached to it.
- 18 July 2014The ability will trigger only if you control each creature on the battlefield with the greatest power as the beginning of combat step begins. If another player controls a creature with the greatest power or tied for the greatest power at that time, the ability won’t trigger at all.
- 18 July 2014The ability will check its condition again as it tries to resolve. If, at that time, another player controls a creature with the greatest power or tied for the greatest power, the ability won’t do anything.
- 18 July 2014“Each creature on the battlefield with the greatest power” may be a single creature if each other creature has less power.
- 18 July 2014The ability can target any creature an opponent controls, not just one that’s tapped.