Strive

Strive is an ability word introduced in Journey into Nyx, where it was connected to the hero theme of the block.

Description
A spell with a strive ability lets you pump more mana into it to increase the number of targets. Similar abilities had been featured before on cards like Fireball and some multikicker cards in Zendikar block.

As you cast a spell with strive, you can choose any number of targets, paying an additional cost for each target beyond the first.

History
The first set after Journey into Nyx to feature Strive was Commander 2020 (Call the Coppercoats).

Rulings

 * You choose how many targets each spell with a strive ability has and what those targets are as you cast it. It's legal to cast such a spell with no targets, although this is rarely a good idea. You can't choose the same target more than once for a single strive spell.
 * The mana cost and converted mana cost of strive spells don't change no matter how many targets they have. Strive abilities affect only what you pay. For example, the converted mana cost of Desperate Stand is always 2.
 * If all of the spell's targets are illegal when the spell tries to resolve, it will be countered and none of its effects will happen. If one or more of its targets are legal when it tries to resolve, the spell will resolve and affect only those legal targets. It will have no effect on any illegal targets.
 * If such a spell is copied, and the effect that copies the spell allows a player to choose new targets for the copy, the number of targets can't be changed. The player may change any number of the targets, including all of them or none of them. If, for one of the targets, the player can't choose a new legal target, then it remains unchanged (even if the current target is illegal).
 * If a spell or ability allows you to cast a strive spell without paying its mana cost, you must pay the additional costs for any targets beyond the first.