Convoke (CR 702.51) is a keyword ability that lets you tap creatures you control to help pay for a spell's mana cost. Each tapped creature reduces the cost by one generic mana or one mana of that creature's color. Crucially, convoke does not require the creature to be able to attack or activate tap abilities — it simply requires the creature to be untapped at the time you cast the spell.
Summoning sickness (CR 302.6) only restricts a creature from attacking or using activated abilities with the tap symbol (or untap symbol). Tapping a creature for convoke is a special action that happens as part of casting a spell (CR 601.2h), not an activated ability, so summoning sickness does not prevent it.
Therefore, a creature that entered the battlefield this turn is perfectly usable for convoke, as long as it is currently untapped. This is a common and powerful interaction in token-generating or creature-flooding strategies.
Example: You cast a 1/1 Goblin token on your first main phase via a spell. Later that same turn, you want to cast End Raze Forerunners (which has convoke). Even though the Goblin has summoning sickness and cannot attack, you may tap it to help pay for the convoke cost, reducing the mana you need to spend.
Unofficial fan resource — not affiliated with or endorsed by Wizards of the Coast. Answers are AI-generated estimates grounded in the Comprehensive Rules and are not a substitute for an official judge. Verify anything match-critical.