Hi there!

Just start playing anivia and I'd like some tips regarding her and 3x3 matches.

I usually get very confused and end up going top and bot depending on the opponent team.

Is there a regular or default lane for anivia in TT?

Or maybe a rule of thumb for that?

anivia and twisted treeline cannot co exist

LOL

Your questions show you do not understand how the game works. Please go play SR where picking meta-champ-item-lane is all in a guide.

Anivia and twisted treeline aren't that good. You need a solo lane to shine and usually top is occupated by your ad carry (tryndamere, noct etc.)

anivia is op on 3s ur all dumb just get 2 roa

Her cc is adequate, but other mages like kennen and casseopeia outshine her.

And there is no default lane for any champ in TT; More like default champs. Really there should be two "higher tier" solo laners and one jungler.

Her walls control the flow of teamfights and cause hilariosity

you can run your ult on your nexus turret from your spawn...
with infinite mana the enemy will never get minions there.

people saying anivia isn't good in 3s have never seen a decent anivia then.. she brings so much to a team its insane. you need to fit her into a good team composition with good players and she can shine