Orb of Chance

My templar has found exactly one orb of chance, and it made a (quite decent for level) rare. 100% success rate!

In all seriousness, the point of the orb of chance isn't to reliably get rares - as far as I'm aware (and this may have changed, I haven't looked into it for a whole) it's the same chance of rare as an item drop has of upgrading from magic to rare. The orb of chance is effectively a "free" drop that you know will be at least magic, but has a regular drop's chances of being higher rarity, and you get to chose the base type of that drop. I don't personally feel it needs to specifically make rares more likely than that.