Dragonborn Champion — ruling 1

Dragonborn Champion's last ability only triggers if 5 or more damage is dealt by the same source at the same time. If a source deals 3 damage to a player and then later deals 2 more damage to the same player, this will not cause the ability to trigger.

Dragonborn Champion : règles, fonctionnement et interactions (MTG)

Dragonborn Champion 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

Trample Whenever a source you control deals 5 or more damage to a player, draw a card.

How it works : Dragonborn Champion

Original English text — Wizards of the Coast / Scryfall

#1July 23, 2021· Wizards of the Coast
Dragonborn Champion's last ability only triggers if 5 or more damage is dealt by the same source at the same time. If a source deals 3 damage to a player and then later deals 2 more damage to the same player, this will not cause the ability to trigger.
No other card is named in this ruling.