Drought

At the beginning of your upkeep, sacrifice this enchantment unless you pay {W}{W}. Spells cost an additional "Sacrifice a Swamp" to cast for each black mana symbol in their mana costs. Activated abilities cost an additional "Sacrifice a Swamp" to activate for each black mana symbol in their activation costs.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6ohj13cldvpb1hhi7hh1qq.