So is it best to buy a second ring if your behind, or if your ahead? or should you just never stack them, basic question but with it's recent price change and being able to pick it up as first item with two pots makes it so tempting to stack in all situations?
It's cost-efficient lane power, which usually means you buy it when you're behind or you're in a tough matchup. Certain champions that benefit from flat HP like Diana will probably stack 2 rings more often than a safer AP champion like Lux. You also might get a second ring if you get first blood very early in the game since 400 gold is exactly enough for a ring, which would give you a really dominant early laning phase.
If you're far ahead of your opponent, you don't need to build cost-efficient early game items. You can just get to your core items quicker.
I believe it's like this.
1) You buy it when you're behind
2) You buy it when you have a slight advantage
3) You don't buy it when you have a huge advantage
If the laning phase is ending really fast and I don't have enough base hp I like to get one just to increase my survivability (without sacrificing mid game power). ex. I'm low level, they took my tower, fights are going down
If you're far ahead of your opponent, you don't need to build cost-efficient early game items. You can just get to your core items quicker.
1) You buy it when you're behind
2) You buy it when you have a slight advantage
3) You don't buy it when you have a huge advantage