World Enchantment, 3B (4) Whenever a player plays a spell, counter it unless its controller pays {3}.1 These days, some wizards are finding that they have a little too much spell left at the end of their mana.
Illus. Harold McNeill
This is not an additional play cost, it is a triggered ability (see Rule 404). [Duelist Magazine #9, Page 60]
The countering effect does not take place until after Nether Void resolves and is in play. It does not affect its own casting or any casting in the same spell stack. [D'Angelo 1995/12/09]
Extended tournaments (see Rule 803) have always banned this card.