Does summoning sickness prevent a creature from using activated abilities that don't require tapping?

Summoning sickness is governed by CR 302.6, which states that a creature cannot attack and cannot use activated abilities with the tap symbol (T) or untap symbol (Q) in their cost unless it has haste or has been under its controller's control since the beginning of their most recent turn.

Crucially, this restriction does NOT extend to activated abilities whose costs have no tap or untap symbol. If an ability just costs mana, life, discarding a card, sacrificing a permanent, or any other non-tap resource, the creature can use it the moment it enters the battlefield — even on the same turn it was played.

This distinction exists because 'summoning sickness' thematically represents a creature being too disoriented to act physically (attacking, tapping), not to use innate powers that don't require exertion in that way.

Concrete Example: You cast Festering Goblin on your main phase. It enters the battlefield with summoning sickness. It has an activated ability: 'When Festering Goblin dies, target creature gets -1/-1 until end of turn.' More relevantly, if it had an ability like '{2}: Do X' (no tap symbol), you could activate that ability immediately, on the very turn it entered. You simply could not tap it to attack or to activate any ability that uses T in its cost.

Referenced rules: CR 302.6 defines the summoning sickness restriction; CR 102.6 (haste) notes how haste bypasses it. The tap/untap symbol restriction in costs is covered under CR 602.5a, which references 302.6 for when tap/untap abilities are restricted.