Lich
Enchantment
Rulings (9)
The last ability will cause you to lose the game even if you somehow manage to have a life total greater than 0 at the time the Lich is put into the graveyard or if some other effect would prevent you from losing for having 0 life. If, on the other hand, some effect such as that from Platinum Angel says that you can't lose the game then even the last ability of the Lich cannot cause you to do so. The ability will just resolve and the game will continue as normal.
Note that usually you will have 0 or less life at the time Lich leaves the battlefield causing you to lose as a State-Based Action before the last ability can even go on the stack.
The last ability will cause you to lose the game even if you somehow manage to have a life total greater than 0 at the time the Lich leaves the battlefield or if some other effect would prevent you from losing for having 0 life. If, on the other hand, some effect such as that from Platinum Angel says that you can't lose the game then even the last ability of the Lich cannot cause you to do so. The ability will just resolve and the game will continue as normal.
Legality
Formats by platform