An additional cost is a cost listed in a spell's rules text, or applied to a spell or ability from another effect, that its controller must pay at the same time that player pays the spell's mana cost or the ability's activation cost. A cost is an additional cost only if it's phrased using the word "additional." Additional costs may be mandatory or optional. Mandatory costs sometimes help.
As an additional cost to cast this spell, sacrifice an artifact or creature. Search your library for an Equipment or Vehicle card, put that card onto the battlefield, then shuffle. An additional cost is something you pay on top of whatever base cost you're using (mana cost or alternative cost).
Typical examples are kicker, buyback, bargain, phrases like "As an additional cost to cast this spell, sacrifice a creature," and commander tax. 53 MTG cards found that are Rules Text: as, additional, cost, discard in the official Magic: The Gathering Database. An additional cost is a cost listed in a spell's rules text, or applied to a spell or ability from another effect, that its controller must pay at the same time they pay the spell's mana cost or the ability's activation cost.
An additional cost is a cost listed in a spell's rules text, or applied to a spell or ability from another effect, that its controller must pay at the same time that player pays the spell's mana cost or the ability's activation cost. A cost is an additional cost only if it's phrased using the word "additional.". An additional cost is a cost you pay in addition to whatever you pay, whether the mana cost or some alternative cost.
You pay both the original cost and the additional cost. It's primarily determined by the mana cost (or ability activation cost), but alternative costs, additional costs, and other cost increases or decreases can play a role. These modifications can come from the abilities of the spell itself or the external effects.
If there's a mandatory additional cost, such as that of Lightning Axe, you must pay it even if you cast it "without paying its mana cost." If the additional cost is optional such as kicker or entwine, you can choose to pay that cost, but you don't get it for free. As an additional cost to cast this spell, sacrifice an artifact or creature. Return target creature or Spacecraft card with mana value 5 or less from your graveyard to the battlefield.
