Text (CH+errata): Discard a card: If the discarded card is a land card, ~this~ deals 2 damage to target player. Any player may activate this ability. [Oracle 2009/07/08]
The discard is a cost. [Aahz 1996/11/07]
The damage done when you discard a land only applies to lands which are discarded by choice using the Land's Edge ability. It does not work on forced discards of any type. [Duelist Magazine #2, Page 8]
You cannot use the Library of Leng ability to place a discarded card on top of your library when using the Land's Edge ability to discard when you want to because this is a discard by choice. [Aahz 1994/07/25]
Extended tournaments (see Rule 913) have banned this card since 1999/10/01.
