Why does Ezreal discount happen before Vex with the new updates?

According to the updated rules in the 2026-03-30 Patch Notes and Rule 356.4, the reason Ezreal's discount is applied before Vex's is due to the distinction between component-specific discounts and total-cost discounts.

Here is the breakdown of why this order is required:

1. Component vs. Total Cost

• Ezreal, Prodigy provides a discount that only affects a specific component of a cost (optional additional costs).
• Vex, Cheerless provides a discount that affects the total cost of the spell.

2. The Application Order (Rule 356.4)

The rules were clarified to ensure consistent math when multiple types of discounts apply to the same card:

• Rule 356.4.c: Discounts that only apply to a component of a cost must be applied as soon as that component is added to the total cost.
• Rule 356.4.d: Discounts that apply to the total cost of a spell must be applied after any discounts that apply only to a component.

Summary

Because Ezreal’s discount is tied to a specific component (the optional additional cost), it is mathematically "locked in" and applied to that component the moment it is added to the cost. Vex’s discount, which applies to the final sum of the spell's cost, must wait until all component-specific adjustments have been calculated.

This sequence prevents ambiguity and ensures that players calculate the cost in a standardized, logical order: Component Discounts → Total Cost Discounts.