Ajani, Inspiring Leader — ruling 1

You may activate Ajani’s first ability without choosing any target. If you do, you will gain 2 life. However, if you do choose a target and the target creature is an illegal target by the time the ability tries to resolve, the ability doesn’t resolve. You won’t gain 2 life.

Ajani, Inspiring Leader — ruling 2

If the target creature is an illegal target by the time Ajani’s second ability tries to resolve, the ability doesn’t resolve. No player will gain life.

Ajani, Inspiring Leader — ruling 3

Ajani’s last ability affects only creatures you control at the time it resolves. Creatures you begin to control later in the turn won’t gain flying or double strike.

Ajani, Inspiring Leader : règles, fonctionnement et interactions (MTG)

Ajani, Inspiring Leader 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

+2: You gain 2 life. Put two +1/+1 counters on up to one target creature. −3: Exile target creature. Its controller gains 2 life. −10: Creatures you control gain flying and double strike until end of turn.

How it works : Ajani, Inspiring Leader

Original English text — Wizards of the Coast / Scryfall

#1July 12, 2019· Wizards of the Coast
You may activate Ajani’s first ability without choosing any target. If you do, you will gain 2 life. However, if you do choose a target and the target creature is an illegal target by the time the ability tries to resolve, the ability doesn’t resolve. You won’t gain 2 life.
No other card is named in this ruling.
#2July 12, 2019· Wizards of the Coast
If the target creature is an illegal target by the time Ajani’s second ability tries to resolve, the ability doesn’t resolve. No player will gain life.
No other card is named in this ruling.
#3July 12, 2019· Wizards of the Coast
Ajani’s last ability affects only creatures you control at the time it resolves. Creatures you begin to control later in the turn won’t gain flying or double strike.
No other card is named in this ruling.

Interactions with other cards

These cards' text mentions Ajani, Inspiring Leader.

Goldmane Griffin

Flying, vigilance When this creature enters, you may search your library and/or graveyard for a card named Ajani, Inspiring Leader, reveal it, and put it into your hand. If you search your library this way, shuffle.