When is it ok to call a 3 bet? Pretty broad I know and I know "it depends", so bare with me here. Say effective stacks are 100bbs deep. From a mathematical standpoint, what would constitute a call? You need the implied odds and I have heard that 20-1 is what you need. This seems high to me and should be lower.

I know that this all is situational like depends on the player, stacks, position, etc. But, I am looking from a general standpoint. Lastly, what type of hands can you call the 3 bet with if you are getting the correct implied odds? In other words, what hands would be profitable to call with? pps? scs?