So if I fall in an elemental pool and take 8 fire, 8 cold, 8 acid damage, and have resist 5 fire and cold, I take 3+3+8=14 damage, but if I have resist 5 fire, cold, acid, lightning, thunder, radiant, necrotic, poison, and everything else under the sun (i.e. resist 5 all), I take 3+8+8=19...