Yule: Mechanics

Ambient: You may cast this for its ambient cost. If you do, change its text by replacing all instances of “enchanted creature” with “each creature you control”. Used on 2 cards: Righteous Gleam, Chilled Armaments

This is a mechanic which features on Auras, exemplifying the way that the Witsolstice vastly expands the potency of enchantments.

Chill factor: Each snow permanent you control counts towards your chill factor. Used on 0 cards:

As the snowfall grows, so too does the magic of Yule; chill factor affects the strengths of many spells.

Splendor: Whenever you cast a spell that targets CARDNAME, [effect]. Used on 0 cards:

Splendor is a 'functional reprint' of the Heroic ability which featured in Theros.

In card text or details pages, write the mechanic's code name (playtest name) between square brackets, like "[Crittercast]", "[Bushido 1]" or "[Delay 4 {2}{R}{R}]". It will be expanded to the mechanic's name plus reminder text, such as "Suspend 4 – {2} {r} {r} . (Rather than cast this spell from your hand,...)"
To expand a mechanic's name but not its reminder text, include parentheses at the end of the square brackets: "[Crittercast()]", "[Delay 9 {R}()]".