Text (UG+errata): Whenever any creature damages a player, for each ~this~ card in play, that player says "~this~" once or ~this~ deals 1 damage to him or her. [Oracle 2009/07/08]
If there are two Ows in play, you need to say "Ow" twice for each card, for a total of four times. If there are N Ows in play, you need to say "Ow" N times N times. This is because each Ow requires you say "Ow" for each Ow card in play. [DeLaney 1998/08/12]
You can use "Ow" in a sentence, such as "Ow, quit it" if you want. [DeLaney 1998/08/12]
If you fail to say the right number of Ows for an Ow, you only take 1 damage from that Ow, not one damage for each "Ow" that you didn't say. [Barclay 1998/08/13]
If there is more than one Ow card in play, each Ow card can do only 1 damage to you each time damage is dealt. [D'Angelo 1998/08/13]
All tournament formats have banned cards from Unglued.
