UPDATED: AUGUST 6TH 2017
Most of the time it's just down to the doorman's discretion and what rules the venue has in place. If you don't bring attention to yourselves and maybe walk-in in small groups you should be ok in most Liverpool's bars, nightclubs. Some venues will have a different door policy to follow so you might need to try a few places first before you all manage to gain entry if you're all drunk and shouting. In short, if they don't let you in you just go somewhere else, plenty of good bars, nightclubs spread out all-over Liverpool who will gladly welcome your business, it's mainly the more upmarket clubs where you might have some trouble on the door.