Humility is a static ability that generates a continuous effect. Per CR 611.3, continuous effects generated by static abilities apply for as long as the permanent with that ability remains on the battlefield. This means Humility's effect is always 'on,' affecting every creature that exists or comes into existence while Humility is in play.
When a new creature enters the battlefield after Humility has already resolved, the game immediately applies all applicable layer effects to that creature. Humility's effect operates in Layer 6 (ability-adding/removing, CR 613.3f) and Layer 7b (power/toughness setting effects, CR 613.4b), stripping all abilities and setting the creature's base power and toughness to 1/1.
This is important: the creature's printed abilities never 'turn on' — they are removed as a state-based consequence of continuous effects, not retroactively. The creature simply enters a world where Humility's blanket effect already governs it.
Concrete example: You cast Serra Angel while your opponent controls Humility. Serra Angel normally has flying and vigilance, but the moment it enters the battlefield, Humility's continuous effect strips both abilities and sets it to 1/1. It is simply a 1/1 creature with no abilities for as long as Humility remains in play.
Note: If another effect grants the creature abilities in a higher layer or later timestamp in the same layer, those interactions must be evaluated through the full layer system (CR 613), but Humility's base removal still applies to any creature entering the battlefield.
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.