Valor in Akros — ruling 1

Valor in Akros's ability affects only creatures you control at the time the ability resolves, including the creature that caused it to trigger. Creatures you begin to control later in the turn won't get +1/+1.

Valor in Akros : règles, fonctionnement et interactions (MTG)

Valor in Akros is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Whenever a creature you control enters, creatures you control get +1/+1 until end of turn.

How it works : Valor in Akros

Original English text — Wizards of the Coast / Scryfall

#1August 7, 2020· Wizards of the Coast
Valor in Akros's ability affects only creatures you control at the time the ability resolves, including the creature that caused it to trigger. Creatures you begin to control later in the turn won't get +1/+1.
No other card is named in this ruling.