Cheapest priced copy (Exodus): $6.49 at Card Kingdom, near mint, their price list as of .
Oath of Lieges 
Enchantment · Rare · Exodus · #11
At the beginning of each player's upkeep, that player chooses target player who controls more lands than they do and is their opponent. The first player may search their library for a basic land card, put that card onto the battlefield, then shuffle.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $6.49 to $6.99 at Card Kingdom
5 rulings from Wizards of the Coast
- 4 October 2004The land card enters under the current player's control.
- 4 October 2004Because the "search" requires you to find a card with certain characteristics, you don't have to find the card if you don't want to.
- 1 August 2008Shuffling the library is part of the optional effect. The player only shuffles if they chose to search.
- 1 October 2009The ability can only target an opponent of the current player.
- 1 October 2009The targeted player controlling more lands than the current player is a part of the targeting requirement. A player can't be targeted by this ability unless it's true, and the ability doesn't resolve if it's no longer true at that time.