To '''pay''' (Japanese: {{ruby|払|はら}}う ''harauHarau'') is to give up [[Life Point|LP]] for a [[card effect]] or [[cost]]. Typically, paying LP is a cost, although some cards involve [[Pays Life Points for effect|paying LP for an effect]].
A player cannot pay more LP than they have left. If paying LP is a requirement to activate a card or effect and the player cannot, that card or effect cannot be activated. If paying LP is part of a [[maintenance cost]] and the player cannot, that card is destroyed (even if the payment is mandatory).<ref>{{cite web |url=http://entertainment.upperdeck.com/yugioh/en/gameplay/faqs/cardfaqs/default.aspx?first=A&last=C |title=Individual Card Rulings [A-C] |publisher=UDE |at=Archfiends |accessdate=26 January 2015 |archiveurl=http://web.archive.org/web/20090217182013/http://entertainment.upperdeck.com/yugioh/en/gameplay/faqs/cardfaqs/default.aspx?first=A&last=C |archivedate=17 February 2009}}</ref> "[[Destructive Draw]]" is the only exception to this rule, which states in its [[card text]] that if its [[control]]ler cannot pay its maintenance cost, instead that player's Life Points become 0.
"[[Spell Economics]]" allows the player to activate [[Spell Card]]s that normally require Life Points to be [[Pays Life Points for cost|paid as a cost]], such as "[[Dimension Fusion]]" and "[[Brain Control]]", without paying those Life Points.