Health Seals

[Thunderfish]

Why is everyone running Health Seal instead of Armor seals now?

[ichbins619]

Armor seals got nerfed so its better to pick health seals in some situations.

[Jay's Elo Service]

If you're playing against, say, an ap mid, the bonus armor you get from 9 seals is lesser than the one you used to get before the nerf, thus making health seals far more efficient against ap-casting champions

[s7LoL]

To add, hp seals are better than armor seals even vs AD champs in all in situations level 1-4. Armor is better in sustain situations vs AD or auto attacking champs even in the early game outside all ins, despite the nerfs.

So AP mids run flat/scaling hp, and supports tend to run all flat hp, or some flat hp + flat armor. Top is still almost always armor as AP tops are semi rare.

Scaling runes tend to not be very viable as even the smallest advantages you lose early game will not make the greater efficiency post level 6/9 enough to justify say losing a few CS because you cannot trade evenly with a person running flat.