608.2c. The controller of the spell or ability follows its instructions in the order written. However, replacement effects may modify these actions. In some cases, later text on the card may modify the meaning of earlier text (for example, “Destroy target creature. It can't be regenerated” or “Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into its owner's graveyard.”) Don't just apply effects step by step without thinking in these cases–read the whole text and apply the rules of English to the text.
611.3c. Continuous effects that modify characteristics of permanents do so simultaneously with the permanent entering the battlefield. They don't wait until the permanent is on the battlefield and then change it. Because such effects apply as the permanent enters the battlefield, they are applied before determining whether the permanent will cause an ability to trigger when it enters the battlefield.
The question has been making the rounds of whether the permanent put onto the battlefield with Arbiter of the Ideal triggers constellation ability. Many judges have correctly answered that, in fact, it does not. Unfortunately, this interaction escaped our notice and the rules that cause this situation produce counterintuitive results, so we're making a change.
If a spell or ability both puts a card onto the battlefield and then creates a continuous effect that changes that card's color or type, that effect will apply simultaneously with the permanent entering the battlefield. These effects tend to say the affected objects "is in addition to its other .“ Clearly that CE will continue to not be part of the object's copiable values, but you should consider the CE to determine if triggered abilities trigger.
This change affects only the Arbiter of the Ideal family of cards, including:
Arbiter of the Ideal
Ashiok, Nightmare Weaver
Chainer, Dementia Master
Dread Slaver
Grave Betrayal
Grimoire of the Dead
Lim-Dûl the Necromancer
Rise from the Grave
My guess is this really never came up before because none of the interactions were that powerful, common, or interesting. Rise from the Grave and Noxious Ghoul was the best I could come up with.
Notably, if an effect that put a card onto the battlefield and then say that the creature ”gains“ an ability (usually haste) , that ability is added after the permanent is already on the battlefield. One card, Hunting Wilds, puts land card onto the battlefield and says the cards ”become 3/3 green creatures with haste." This CE also is created after the cards are already on the battlefield, so the lands won't trigger Soul Warden, for example.
My apologies for missing this interaction earlier and the resulting confusion. But now drafting Arbiter is way more fun.
Edited Nathan Long (May 9, 2014 05:08:15 PM)