Evolutionary Escalation — ruling 1

You choose two targets for Evolutionary Escalation’s ability as it’s put onto the stack. No player may cast spells or activate abilities during your turn before this happens.

Evolutionary Escalation — ruling 2

If there aren’t two legal targets for Evolutionary Escalation’s ability as it’s put onto the stack, it’s taken off the stack and no creature gets +1/+1 counters.

Evolutionary Escalation — ruling 3

If one target becomes illegal before Evolutionary Escalation’s ability resolves, you’ll put three +1/+1 counters on the target that’s still legal.

Evolutionary Escalation : règles, fonctionnement et interactions (MTG)

Evolutionary Escalation 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

At the beginning of your upkeep, put three +1/+1 counters on target creature you control and three +1/+1 counters on target creature an opponent controls.

How it works : Evolutionary Escalation

Original English text — Wizards of the Coast / Scryfall

#1November 8, 2016· Wizards of the Coast
You choose two targets for Evolutionary Escalation’s ability as it’s put onto the stack. No player may cast spells or activate abilities during your turn before this happens.
No other card is named in this ruling.
#2November 8, 2016· Wizards of the Coast
If there aren’t two legal targets for Evolutionary Escalation’s ability as it’s put onto the stack, it’s taken off the stack and no creature gets +1/+1 counters.
No other card is named in this ruling.
#3November 8, 2016· Wizards of the Coast
If one target becomes illegal before Evolutionary Escalation’s ability resolves, you’ll put three +1/+1 counters on the target that’s still legal.
No other card is named in this ruling.