Quote Originally Posted by namhoang909 View Post
[...] since Olivie appears in banner with "increase summon rate" i thought chance can be more than 3%, right?
[...]
It doesn't work like that buddy, let's explain it with the present units shall we?

The odds of you rolling a black is 3% (0.03) always, then, when you managed to roll a black, it decides which unit you get, there are like 9? black gacha units atm so every one of those have a 1/9 chance to appear [11.11% (0.11)] and the chances of getting the spotlight unit are doubled(?) (22.22% (0.22)]

Now the odds of one rolling the spotlight black from premium summon are 0.03 * 0.22 = 0.0066 (0.66%) which is 2/3 the chance of rolling a black from a rare summon (1%)

That's why many players say that aiming for a black is a waste, and aiming for your waifu (in case of her beign black) is even worse

If you have the SC to do it and you want to, then do it, we are no one to stop you, but i recomend having a buffer of 30+ SC for STA refills for collection events