Alternative cost

An alternative cost (alternate cost, alternate playing cost, or APC) is another way to pay for a spell besides its normal mana cost. Cards with alternative costs were first introduced in Alliances, with the pitch spells. 
==Functionality==
Alternate costs are usually optional and enabled by abilities which cause the spell to have a modified effect, provide an opportunity to pay a lower-than-normal cost, or change the circumstances in which the spell can be cast. For instance, paying an alternate cost may change the timing restrictions for casting a spell or which zone it can be played from. The cost may be entirely in mana, or may involve other resources. Even if the alternate cost is being paid and is entirely in mana, effects that mention the spell's "mana cost" are still referring to the normal cost printed on the card, not the alternate cost.
These costs are most often specified by abilities on the card itself rather than as part of another card's effects, with the exception of effects that allow another card to be played "without paying its mana cost". When an effect allows playing a card "for free" this way, it's not possible to also choose to pay a different alternate cost, such as one provided by the card's own abilities.
Alternate costs often lead to similar effects and strategies as additional costs and miscellaneous cost increases and reductions. However, the rules governing each of these are slightly different, so care should be taken to observe the distinctions during play. Note that additional costs or other increases or decreases are still applied to alternative costs just as they would be to a typical mana cost; alternative costs only "replace" the original mana cost component of the total cost.
Abilities that put permanents into play or copies of spells on the stack may seem like alternative costs for those permanents or spells, but technically they were not cast at all in those cases, so no alternative cost was paid.
==Rules==
==Types of reduced costs==
Below are most possible costs one can spend in order to lessen or supplant a card's mana cost:
* Alternative Mana (such as Hybrid mana)
* Life (such as Phyrexian mana)
* Cards in Hand (Discard Cards)
* Sacrifice Permanents on the Battlefield
* Return a Permanent to Owner's Hand
* Tap Permanents on the Battlefield
* Cards in Graveyard
* Cards in Library
* Spend Time
* Future Mana
* Future Draws
* Future Steps/Phases
* Possession of Permanents on the Battlefield
* Granting Opponent Life
* Opponent Has Taken Certain Actions
* Condition Has Happened
* Another Player Pays a Portion
Technically, a number of the above examples are simply a "different way to pay for the mana cost" rather than a true alternate cost which completely replaces the mana cost. However, few if any abilities care about this distinction.
==Alternative cost keywords==
This is a list of alternative costs that exist as keywords.
Keywords that change the circumstances of a spell's casting if an alternate cost is paid:
*Escape allows casting from the graveyard while exiling other cards from it
*Flashback allows casting from the graveyard
*Madness allows casting as the spell is being discarded
*Miracle allows casting as the spell is being drawn
*Plot allows pre-paying the plot cost and exiling the spell to cast the spell on a future turn for free
Keywords that make it easier to pay for the spell:
*Emerge allows the sacrifice of another creature to help pay for an alternate cost
*Foretell allows pre-paying to pay a usually lower cost on a later turn
*Prowl damage dealt by certain creatures enables an alternate cost
*Spectacle opponent's life loss enables an alternate cost
*Surge spells cast earlier in a turn enable an alternate cost
*Suspend an alternate cost is paid, but the spell resolves several turns later
*Prototype a creature is cast with weaker power and toughness
*Madness and Miracle These abilities, which allow casting a spell under special timing rules, also typically reduce the cost
Keywords that change or add to the spell's effects when an alternate cost is paid:
*Awaken turns land in play into a creature
*Bestow a creature is cast as an enchantment
*Blitz a creature only lasts one turn, then draws a new card
*Cleave cast the spell without one or more words in its card text
*Dash grants a creature haste, but returns it to hand at end of turn
*Disturb cast the card transformed from the graveyard
*Evoke a creature is cast and immediately sacrificed, creating a sorcery-like effect
*Morph a creature is cast face down, but can be turned face up later
*Mutate a creature is cast to merge with another non-human creature
*More Than Meets the Eye a creature is cast converted
*Overload a spell affects all possible targets instead of just one
*Escape, Foretell, Madness, Prowl, Spectacle, and Surge These abilities, which are generally used to create more opportunities for casting, may also enable additional effects, as in "If the prowl cost was paid..." or "If this card was foretold..."
Cascade doesn't provide an alternate cost for the card it's on, but does trigger to sometimes allow an additional spell to be cast without paying its mana cost, which is an alternate cost.
Adventure spells, Modal double-faced cards, and Prototype cards can each be cast with an entirely different set of characteristics from their primary characteristics, including mana cost. However, this results in a secondary spell entirely different from the primary one, so the cost paid is the true mana cost for that spell, not an alternate cost.
Some abilities like Ninjutsu and Unearth put the card into the battlefield without actually casting it, and thus don't technically use alternate costs. Assist, Convoke, and Delve allow certain actions to help pay for a spell's cost instead of normal mana expenditure, but the cost itself remains the same.
==References==