What if armor and mr gave additive % armor/mr-reduction so its easier for players to calculate
The math to calculate effective health based on a champion's armor and mr isn't a fun or practical element for players to take advantage of in game. What if the armor and mr items were reworked so they have roughly the same power as they do now but instead grant a flat % physical/magic damage reduction.
For example, let's say Spirit Visage gives 25% magic damage reduction, and Abyssal Mask gives 10% magic damage reduction. If you bought both you would have a combined 35% magic damage reduction.
This is much easier to grasp at a glance than 100 / (100 + total-magic-resist). And it's not hidden from new players. I don't have to look up a formula on an obscure forum post to understand how effective an armor or mr item is in the game I'm playing.