Tithe

Search your library for a Plains card. If target opponent controls more lands than you, you may search your library for an additional Plains card. Reveal those cards, put them into your hand, then shuffle.

World Championship Decks 1998

Visions

Search your library for a plains card. If you control fewer lands than target opponent, you may search your library for an additional plains card. Reveal those cards to all players and put them into your hand. Shuffle your library afterwards.

Because 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.

Counts lands on resolution, not on announcement.