After upgrading items a certain amount of times you meet a max number of upgrades- Legendary- 100 Epic- 80 Rare- 60 Magic- 40 Common- 20 And after you can instead of upgrade it you can break the level limit thats where stones come in. You need a certain amount to upgrade it. Ex. Legendary Max Level- 100 Needs- X Gold / X of X Stones After breaking- 105 You can break it as many times as you want as long as you have the materials.