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. The controller of The Abyss controls the ability, but the current player chooses what they sacrifice. Since you can only choose basic lands, your non-basic lands are all going to be sacrificed. 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. This summary is collected from rulings made by officials and network representatives of Wizards of the Coast, along with a number of unofficial rulings also collected from the net.