ExtortExtort is a triggered ability. “Extort” means “Whenever you cast a spell, you may pay . If you do, each opponent loses 1 life and you gain life equal to the total life lost this way.”
If a permanent has multiple instances of extort, each triggers separately. (CR 702.101) (Whenever you
castTo cast a spell is to take it from the zone it’s in (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. A player may cast a spell if they have priority. See rule 601, “Casting Spells.”
To cast a card is to cast it as a spell. (CR 701.5) a spell, you may pay
. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you
tapTo tap a permanent, turn it sideways from an upright position. Only untapped permanents can be tapped. (CR 701.26) a Swamp for mana, add an additional
.