Rulings are collected from many sources. See credits and disclaimer at the end of the file for details. Three Kingdoms, Starter, and Starter 2000 cards do not yet have official Oracle card texts, so rulings on them are based on Oracle texts made by NetReps.
Complete text is included for cards from all expansions.
These rulings are updated monthly. Land Tax counts lands at the beginning of upkeep before even a mana source can be used. The life total changes for a player only when it comes into play under that player's control. The last sentence doesn't apply in this case since the Lich didn't leave play. While this work is not officially issued by Wizards of the Coast, it is the official collected rulings from official sanctioned representatives of and publications by Wizards of the Coast.