The text used on a card produces some form of effect. However, this is does not include the Flavor Text, Artist or any copyright and card or set number information.
If the effect requires gameplay actions where they can't all be completed, see "Empty Shot".
Effects written on a card only affect cards that are in the battle zone unless specified on the card itself (such as cards that apply to the deck or mana zone) or only applicable to other game zones (such as discard effects only affecting the hand, or cards that bring others from the Hyperspatial Zone).
Although all effects can stack, some overlap abilities create no difference, such as multiple instances of the same Breaker like a creature having 2x "Double Breaker" abilities.