Drought

Enchantment -
At the beginning of your upkeep, sacrifice Drought unless you pay {W}{W}. <CR>
Spells cost an additional "Sacrifice a Swamp" to play for each black mana symbol in their mana costs. <CR>
Activated abilities cost an additional "Sacrifice a Swamp" to play for each black mana symbol in their activation costs.

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

Enchantment -
At the beginning of your upkeep, sacrifice Drought unless you pay {W}{W}. <CR>
As an additional cost to play spells with {B} in their mana costs and activated abilities with {B} in their activation costs, that spell or ability's controller sacrifices a Swamp for each {B} in that cost.

Enchantment -
At the beginning of your upkeep, sacrifice Drought unless you pay {W}{W}. <CR>
Spells cost an additional "Sacrifice a Swamp" to play for each black mana symbol in their mana costs. <CR>
Activated abilities cost an additional "Sacrifice a Swamp" to play for each black mana symbol in their activation costs.