Karlov of the Ghost Council — ruling 1

The ability triggers just once for each life-gaining event, whether it's 1 life from an attacking creature with lifelink or 4 life from Faith's Fetters.

Karlov of the Ghost Council — ruling 2

A creature with lifelink dealing combat damage is a single life-gaining event. For example, if two creatures you control with lifelink deal combat damage at the same time, the ability will trigger twice. However, if a single creature with lifelink deals combat damage to multiple players or permanents at the same time (perhaps because it has trample or was blocked by more than one creature), the ability will trigger only once.

Karlov of the Ghost Council — ruling 3

In a Two-Headed Giant game, life gained by your teammate won't cause the ability to trigger, even though it causes your team's life total to increase.

Karlov of the Ghost Council : règles, fonctionnement et interactions (MTG)

Karlov of the Ghost Council 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 two +1/+1 counters on Karlov. , Remove six +1/+1 counters from Karlov: Exile target creature.

Complete guide

Karlov of the Ghost Council is a powerful Orzhov commander that rewards you for every instance of life gain. By turning small life increments into massive power, Karlov quickly becomes a lethal threat that can also control the board. This Spirit Advisor excels in decks that focus on frequent, small bursts of healing rather than single large heals.

Scaling with Life Gain

Karlov's first ability is a triggered ability that watches for any event where you gain life. Each time a life-gaining event occurs, regardless of how much life was gained, you place exactly two +1/+1 counters on Karlov. This means ten instances of gaining 1 life are significantly better for Karlov than one instance of gaining 10 life, as the former results in twenty counters while the latter only provides two.

Step-by-Step Resolution

First, an effect or combat damage causes you to gain life, putting Karlov's triggered ability on the stack. Once that ability resolves, the two +1/+1 counters are placed on him. To use his second ability, you must pay the mana cost and remove six +1/+1 counters as a cost to activate it. If you have enough counters, you then choose a target creature to be exiled upon resolution.

Common Mistakes

A common misconception involves how lifelink interacts with multiple creatures. If three creatures with lifelink deal combat damage simultaneously, these are three separate events, triggering Karlov three times. However, if a single creature with lifelink deals damage to multiple blockers, it is still just one event and one trigger. Additionally, in Two-Headed Giant, life gained by your teammate does not trigger Karlov, even though your team's life total goes up.

Strategic Timing

Because Karlov's exile ability is an activated ability, you can use it at instant speed. It is often best to keep Karlov's counters available during your opponent's turn to threaten their key creatures. Remember that you can respond to your own life-gain triggers by activating his exile ability if he already has enough counters, or wait for the counters to land to surprise an opponent during combat.

Interaction examples

Individual Triggers

If you cast a spell that says 'You gain 1 life for each creature you control' and you control five creatures, you gain all that life at once. This is one event, so Karlov only gets two +1/+1 counters. If the spell said 'For each creature you control, you gain 1 life,' these would be separate events, triggering Karlov five times for a total of ten counters.

Combat with Lifelink

You attack with two different creatures that have lifelink. When they both deal combat damage at the same time during the combat damage step, two separate triggers are put on the stack. Karlov will receive a total of four +1/+1 counters once both triggers resolve.

Removing Counters to Control

Karlov currently has six +1/+1 counters on him. An opponent casts a large creature. You can pay one White and one Black mana and remove all six counters to target that creature. Even if the opponent tries to kill Karlov in response, the ability is already on the stack and will still exile the target.

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

How it works : Karlov of the Ghost Council

Original English text — Wizards of the Coast / Scryfall

#1November 4, 2015· Wizards of the Coast
The ability triggers just once for each life-gaining event, whether it's 1 life from an attacking creature with lifelink or 4 life from Faith's Fetters.
No other card is named in this ruling.
#2November 4, 2015· Wizards of the Coast
A creature with lifelink dealing combat damage is a single life-gaining event. For example, if two creatures you control with lifelink deal combat damage at the same time, the ability will trigger twice. However, if a single creature with lifelink deals combat damage to multiple players or permanents 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.
#3November 4, 2015· Wizards of the Coast
In a Two-Headed Giant game, life gained by your teammate won't cause the ability to trigger, even though it causes your team's life total to increase.
No other card is named in this ruling.