AmassTo amass [subtype] N means “If you don’t control an Army creature, create a 0/0 black [subtype] Army creature token. Choose an Army creature you control. Put N +1/+1 counters on that creature. If it isn’t a [subtype], it becomes a [subtype] in addition to its other types.”
A player “amassed” after the process described in rule 701.47a is complete, even if some or all of those actions were impossible.
The phrases “the Army you amassed” and “the amassed Army” refer to the creature you chose, whether or not it received counters.
Some older cards were printed with amass N without including a subtype. Those cards have received errata in the Oracle card reference so that they read “amass Zombies N.” (CR 701.47) Goblins 1. If this spell was
castTo cast a spell is to take it from the zone it’s in (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. A player may cast a spell if they have priority. See rule 601, “Casting Spells.”
To cast a card is to cast it as a spell. (CR 701.5) from a graveyard,
amassTo amass [subtype] N means “If you don’t control an Army creature, create a 0/0 black [subtype] Army creature token. Choose an Army creature you control. Put N +1/+1 counters on that creature. If it isn’t a [subtype], it becomes a [subtype] in addition to its other types.”
A player “amassed” after the process described in rule 701.47a is complete, even if some or all of those actions were impossible.
The phrases “the Army you amassed” and “the amassed Army” refer to the creature you chose, whether or not it received counters.
Some older cards were printed with amass N without including a subtype. Those cards have received errata in the Oracle card reference so that they read “amass Zombies N.” (CR 701.47) Goblins 3 instead. (To
amassTo amass [subtype] N means “If you don’t control an Army creature, create a 0/0 black [subtype] Army creature token. Choose an Army creature you control. Put N +1/+1 counters on that creature. If it isn’t a [subtype], it becomes a [subtype] in addition to its other types.”
A player “amassed” after the process described in rule 701.47a is complete, even if some or all of those actions were impossible.
The phrases “the Army you amassed” and “the amassed Army” refer to the creature you chose, whether or not it received counters.
Some older cards were printed with amass N without including a subtype. Those cards have received errata in the Oracle card reference so that they read “amass Zombies N.” (CR 701.47) Goblins X, put X +1/+1
countersTo counter a spell or ability is to cancel it: remove it from the stack without resolving it. A counter on an object or player is instead a marker that changes characteristics or interacts with rules or abilities; for example, a +1/+1 counter modifies a creature’s power and toughness. (CR 701.6; 122.1) on an Army you control. It's also a Goblin. If you don't control an Army,
createTo create one or more tokens with certain characteristics, put the specified number of tokens with the specified characteristics onto the battlefield.
If a replacement effect applies to a token being created, that effect applies before considering any continuous effects that will modify the characteristics of that token. If a replacement effect applies to a token entering the battlefield, that effect applies after considering any continuous effects that will modify the characteristics of that token.
Previously, an effect that created tokens instructed a player to “put [those tokens] onto the battlefield.” Cards that were printed with that text have received errata in the Oracle card reference so they now “create” those tokens. (CR 701.7) a 0/0 black Goblin Army creature token first.)
FlashbackFlashback appears on some instants and sorceries. It represents two static abilities: one that functions while the card is in a player’s graveyard and another that functions while the card is on the stack. “Flashback [cost]” means “You may cast this card from your graveyard if the resulting spell is an instant or sorcery spell by paying [cost] rather than paying its mana cost” and “If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack.” Casting a spell using its flashback ability follows the rules for paying alternative costs in rules 601.2b and 601.2f–h. (CR 702.34) (You may
castTo cast a spell is to take it from the zone it’s in (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. A player may cast a spell if they have priority. See rule 601, “Casting Spells.”
To cast a card is to cast it as a spell. (CR 701.5) this card from your graveyard for its
flashbackFlashback appears on some instants and sorceries. It represents two static abilities: one that functions while the card is in a player’s graveyard and another that functions while the card is on the stack. “Flashback [cost]” means “You may cast this card from your graveyard if the resulting spell is an instant or sorcery spell by paying [cost] rather than paying its mana cost” and “If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack.” Casting a spell using its flashback ability follows the rules for paying alternative costs in rules 601.2b and 601.2f–h. (CR 702.34) cost. Then
exileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) it.)