Does a creature lose its abilities when Humility is on the battlefield and another effect tries to grant it an ability?

Humility is a static enchantment with two continuous effects: it sets all creatures' power and toughness to 1/1, and it removes all abilities from all creatures. These effects are applied in the layer system defined by CR 613.

Ability-granting and ability-removing effects both operate in Layer 6 (ability-adding and ability-removing effects, CR 613.3). When two effects interact in the same layer, timestamp order determines which applies last (CR 613.7). If Humility entered the battlefield after the effect granting an ability, Humility's removal effect has the later timestamp and wins, stripping the granted ability. If Humility entered first, the granted ability sticks — but only until Humility's timestamp is newer, which for a permanent static effect means it continuously applies, so any ability granted by a newer effect would survive. The key is timestamp comparison within Layer 6.

In practice, because Humility is usually already on the battlefield when other effects try to grant abilities, Humility's continuous removal typically has an older timestamp. A newer effect (e.g., an Aura or equip that enters later) granting an ability would actually keep that ability because it has the newer timestamp. However, if Humility entered after the granting effect, it strips that ability.

Concrete example: Glorious Anthem (+1/+1 and no ability grant) is irrelevant here, so consider instead: a creature has Trample granted by an older Aura, then Humility enters. Humility now has the newer timestamp in Layer 6, so it removes Trample. The creature loses Trample. But if the Aura were attached after Humility entered, the Aura's granted Trample would have the newer timestamp and the creature would keep Trample (though Humility's own text — itself an ability — is also subject to this logic, handled by CR 613.1f dependency rules).

Because of the dependency rules (CR 613.8), effects that remove abilities are considered before effects that grant abilities when one depends on the other, which can further complicate interactions. Always check which effect entered the battlefield most recently to determine the winner in Layer 6.