Liliana, the Necromancer — ruling 1

For Liliana’s last ability, the creatures you’ll return to the battlefield are chosen after the target creatures are destroyed. No player may take actions between the time you choose two creature cards to return and the time they’re returned. The destroyed cards can be among those returned to the battlefield.

Liliana, the Necromancer — ruling 2

If any abilities trigger on the target creatures being destroyed, those abilities won’t be put onto the stack until after you’ve put creature cards onto the battlefield from graveyards.

Liliana, the Necromancer — ruling 3

You may activate Liliana’s last ability without choosing any target creatures. You’ll just put up to two creature cards onto the battlefield from graveyards. However, if you choose any targets and all of those targets become illegal before the ability tries to resolve, the ability won’t resolve and you won’t put any cards onto the battlefield.

Liliana, the Necromancer — ruling 4

In a multiplayer game, if a player leaves the game, all cards that player owns leave as well. If you leave the game, any permanents you control from Liliana’s third ability that came from other players’ graveyards are exiled.

Liliana, the Necromancer : règles, fonctionnement et interactions (MTG)

Liliana, the Necromancer 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

+1: Target player loses 2 life. −1: Return target creature card from your graveyard to your hand. −7: Destroy up to two target creatures. Put up to two creature cards from graveyards onto the battlefield under your control.

How it works : Liliana, the Necromancer

Original English text — Wizards of the Coast / Scryfall

#1July 13, 2018· Wizards of the Coast
For Liliana’s last ability, the creatures you’ll return to the battlefield are chosen after the target creatures are destroyed. No player may take actions between the time you choose two creature cards to return and the time they’re returned. The destroyed cards can be among those returned to the battlefield.
No other card is named in this ruling.
#2July 13, 2018· Wizards of the Coast
If any abilities trigger on the target creatures being destroyed, those abilities won’t be put onto the stack until after you’ve put creature cards onto the battlefield from graveyards.
No other card is named in this ruling.
#3July 13, 2018· Wizards of the Coast
You may activate Liliana’s last ability without choosing any target creatures. You’ll just put up to two creature cards onto the battlefield from graveyards. However, if you choose any targets and all of those targets become illegal before the ability tries to resolve, the ability won’t resolve and you won’t put any cards onto the battlefield.
No other card is named in this ruling.
#4July 13, 2018· Wizards of the Coast
In a multiplayer game, if a player leaves the game, all cards that player owns leave as well. If you leave the game, any permanents you control from Liliana’s third ability that came from other players’ graveyards are exiled.
No other card is named in this ruling.