Trelasarra, Moon Dancer — ruling 1

If you gain life at the same time Trelasarra, Moon Dancer is dealt lethal damage, it dies before its triggered ability can put a +1/+1 counter on it, but you will still scry 1.

Trelasarra, Moon Dancer — ruling 2

An ability that triggers "whenever you gain life" triggers just once for each life gain event, no matter how much life you gain.

Trelasarra, Moon Dancer — ruling 3

Each creature with lifelink dealing combat damage causes a separate life gain event. For example, if two creatures you control with lifelink deal combat damage at the same time, a "whenever you gain life" ability will trigger twice. However, if a single creature you control with lifelink deals combat damage to multiple creatures, players, and/or planeswalkers at the same time (perhaps because it has trample or was blocked by more than one creature), the ability will trigger only once.

Trelasarra, Moon Dancer : règles, fonctionnement et interactions (MTG)

Trelasarra, Moon Dancer 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 you gain life, put a +1/+1 counter on Trelasarra and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Complete guide

Trelasarra, Moon Dancer is a powerful Selesnya engine that turns every instance of life gain into permanent growth and card selection. This legendary Elf Cleric rewards specialized life-gain decks by growing larger while ensuring you always draw exactly what you need. Whether you are gaining one life or twenty, Trelasarra watches over your progress with grace.

Understanding the Trigger

Trelasarra, Moon Dancer has a triggered ability that responds to any 'life gain event.' This means whenever your life total increases, the ability goes on the stack. Crucially, the amount of life gained doesn't change the number of counters; gaining 5 life once triggers the ability once, providing a single +1/+1 counter and a scry 1. However, multiple separate sources of life gain will trigger Trelasarra multiple times, allowing her to grow rapidly.

Step-by-Step Resolution

When a spell or ability causes you to gain life, Trelasarra's ability is placed on the stack. First, you put a +1/+1 counter on Trelasarra, Moon Dancer. Immediately after that, you scry 1, which means you look at the top card of your library and choose to either leave it there or put it on the bottom. If Trelasarra is no longer on the battlefield when the ability resolves, you won't place the counter, but you will still get to scry 1.

Timing and Lethal Damage

A common mistake involves combat math and lethal damage. If Trelasarra is dealt damage equal to her toughness at the same time you gain life (for example, via a creature with lifelink blocking her), she will be destroyed by state-based actions before her trigger can resolve. While you still get to scry, the +1/+1 counter cannot be placed on a creature that is already in the graveyard.

When to Play Trelasarra

Trelasarra is most effective when played early, ideally on turn two following a mana accelerant. Because her ability triggers on every instance of life gain, she pairs best with repeated, small life-gain effects rather than one large burst. This allows you to manipulate the top of your deck every turn while building a massive threat that demands an answer from your opponent.

Interaction examples

Early Acceleration

Llanowar Elves

On turn one, you play Llanowar Elves. On turn two, you tap the Elves for green mana and use a white source to cast Trelasarra, Moon Dancer. This allows you to start your life-gain engine as early as possible, ensuring that any subsequent life-gain spells you play will immediately trigger her scry and counter ability.

Fixing Your Draws

Birds of Paradise

If you have Birds of Paradise on the battlefield, you can use it to produce the specific white or green mana needed to cast Trelasarra. Once Trelasarra is out, every time you gain life, you scry 1. This synergy helps you dig through your library to find more Birds of Paradise or other utility creatures, ensuring you don't stall out on land draws during the mid-game.

Guide written with AI from the official text and rulings. Official English text prevails.

How it works : Trelasarra, Moon Dancer

Original English text — Wizards of the Coast / Scryfall

#1July 23, 2021· Wizards of the Coast
If you gain life at the same time Trelasarra, Moon Dancer is dealt lethal damage, it dies before its triggered ability can put a +1/+1 counter on it, but you will still scry 1.
No other card is named in this ruling.
#2July 23, 2021· Wizards of the Coast
An ability that triggers "whenever you gain life" triggers just once for each life gain event, no matter how much life you gain.
No other card is named in this ruling.
#3July 23, 2021· Wizards of the Coast
Each creature with lifelink dealing combat damage causes a separate life gain event. For example, if two creatures you control with lifelink deal combat damage at the same time, a "whenever you gain life" ability will trigger twice. However, if a single creature you control with lifelink deals combat damage to multiple creatures, players, and/or planeswalkers at the same time (perhaps because it has trample or was blocked by more than one creature), the ability will trigger only once.
No other card is named in this ruling.