Chandra's Spitfire — ruling 1

Combat damage is the damage that's dealt automatically by attacking and blocking creatures. Any other damage is noncombat damage, even if it's dealt during a combat phase by an attacking or blocking creature.

Chandra's Spitfire — ruling 2

The last ability of Chandra's Spitfire triggers just once for each event in which an opponent is dealt noncombat damage, regardless of how much damage that player is dealt.

Chandra's Spitfire — ruling 3

In a multiplayer game, if a source deals damage to multiple opponents at the same time, the last ability of Chandra's Spitfire will trigger as many times as there are opponents who were dealt damage.

Chandra's Spitfire : règles, fonctionnement et interactions (MTG)

Chandra's Spitfire 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

Flying Whenever an opponent is dealt noncombat damage, this creature gets +3/+0 until end of turn.

How it works : Chandra's Spitfire

Original English text — Wizards of the Coast / Scryfall

#1July 12, 2019· Wizards of the Coast
Combat damage is the damage that's dealt automatically by attacking and blocking creatures. Any other damage is noncombat damage, even if it's dealt during a combat phase by an attacking or blocking creature.
No other card is named in this ruling.
#2July 12, 2019· Wizards of the Coast
The last ability of Chandra's Spitfire triggers just once for each event in which an opponent is dealt noncombat damage, regardless of how much damage that player is dealt.
No other card is named in this ruling.
#3July 12, 2019· Wizards of the Coast
In a multiplayer game, if a source deals damage to multiple opponents at the same time, the last ability of Chandra's Spitfire will trigger as many times as there are opponents who were dealt damage.
No other card is named in this ruling.