We had a interesting (corner-case) discussion with fellow Judges about continuous effects and how to apply them.
What we couldn't find in the Comprehensive Rules is if continuous effects are applied one effect on all objects at a time, or do we look at one object on its own at a time and apply effects?

Our case was Blood Moon and Glaciers and dual lands.
We understand the dependency between the two, but what if there are mountains involved…
We would like to know if we can look at lands separately or do we apply one enchantment's effect at a time, and which rule number to look at to find this info.

The effect of Glaciers is dependent on Blood Moon, because Blood Moon will change what Glaciers will apply to. Even if there are Mountains already on the battlefield, we will always apply the effect of Blood Moon first, then we apply the effect of Glaciers (on the Mountains and the nonbasics that just became Mountains).

613.7a An effect is said to “depend on” another if (a) it’s applied in the same layer (and, if applicable, sublayer) as the other effect (see rules 613.1 and 613.3); (b) applying the other would change the text or the existence of the first effect, what it applies to, or what it does to any of the things it applies to; and © neither effect is from a characteristic-defining ability or both effects are from characteristic-defining abilities. Otherwise, the effect is considered to be independent of the other effect.

Nathan Long
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