What 'ante' is?

I bet you have heard about ante cards in MtG and you surely know that they are banned in every format. But, do you know more? If not, pleas read a card on the right side and make a blind guess what it could be. The word 'ante' does not give any clue. What is it? Why these cards are banned? We will find out in a minute.

Playing for ante is an unofficial variant format where at the beginning of the game each player puts a random card from his or her library into an ante zone and then the winner of the game would get permanent ownership of all the cards in the ante zone.

Wizards printed in total 9 ante cards: Amulet of Quoz, Bronze Tablet, Contract from Below, Darkpact, Demonic Attorney, Jeweled Bird, Rebirth, Tempest Efreet, Timmerian Fiends. Each card has text Remove ~ from your deck before playing if you're not playing for ante. So, in fact to use this card you are forced to play it for ante. However, players did not like having to bet valuable cards and so rarely played for ante. What is more, playing for ante could cause official tournaments to be classed as gambling and would therefore have to adhere to the laws governing. That's why they got banned. Timmerian Fiends was the last ante card, printed in  expansion set Homelands in 1995.

Why am I writing about it? Well, this article is specially dedicated those who have heard about ante mechanic, but didn't want / didn't have time to check what it is and as well for those who heard about it, but on daily basis put off their duties. In our life, we must be inquisitive and develop ourselves all the time, because our knowledge will benefit one day. The smarter you are, the more possibilities await!