There is no hard & fast rule in MTT depending on Bubble, FT, Remaining Rebuy's, etc.
However, if you are looking for a general rule then use 10BB as your watermark.
Your next questions should be: "With what hands?" "What Positions?" This gets complicated, but if you know enough to not waste your time limping and 2x raising with <10BB then you should see some deeper results more often.
Remember - you still need to win your races.
GL GL,
HOUDINI9
Thank you for the answer!
The hands i actually know
I was confused about the stack. You think that 20bb stacks still good for 3betting?
I think that with this stack when you 3bet the pot will be 8-10bbs and you will be pot comimtted
I started thinking about it today after a bad bead, botton raises, SB folds, i was on BB with 20bb and shoves with AQs and he hits a 9, he had A9o, 130 players to the prize pool (1100 players registrated) then i started to think if the right thing was a 3bet