EOT Lifegain Trigger Question

[ISBPathfinder]

So there are a number of cards such as Crested Sunmare, Angelic Accord, The Book of Exalted Deeds to name a few that trigger an effect if you gained life in the turn. I guess I wanted to check exactly how they work. I assume they check to see if their required life has been gained in the turn when they would trigger at end of turn before they go on the stack rather than going on the stack and checking when they resolve.

A big reason as to why I ask is because I want to know if Norin the Wary with Soul's Attendant effects can be stacked to resolve first but I suspect that I have to have gained life before they go on the stack. Just confirming as I couldn't say with absolute certainty that it wouldn't work.

[lyonhaert]

The cards have rulings that explain:

Crested Sunmare's triggered ability won't trigger unless you've gained life in the turn before the end step began. It can't be satisfied by another triggered ability causing you to gain life during that end step.

If you haven't gained 4 or more life during the turn when the end step begins, the ability won't trigger at all. Gaining life during the end step won't cause the ability to trigger.

[peteroupc]

Crested Sunmare, Angelic Accord, and The Book of Exalted Deeds all have abilities of the form "At the beginning of [step or phase], if [condition], ..." (and so do Land Tax, Might Makes Right, Ana Sanctuary, Gisela, the Broken Blade, and Resplendent Angel).

In general, however, an ability of the form "At the beginning of [step or phase], if [condition], ..." triggers only at the beginning of the given step or phase and only if the given condition is true at that moment (C.R. 603.4, 603.2), and that ability will get to resolve only if that condition still holds upon resolving (C.R. 603.4, 608.2a). Nothing you do during that step or phase will change whether that ability will trigger.

See also this thread and this thread.