How common are the card rarities in Arena?

Solution 1:

This is according to my own experience. I have 257 arena wins and I like to keep stats. I searched previously but couldn't find an official source for this.

1st, 10th, 20th, 30th pick in Arena are always rare or higher: I call this Rare Turn, the others are normal turns.

At any normal turn, you can get one of these sets:

  • 3 free
  • 2 free 1 common
  • 1 free 2 common
  • (possibly 3 common as well didn't pay attention, can't verify this)
  • 1 Rare turn ( % not sure I would guess about 5% - 10%)

In a normal turn roughly you have a 60% chance of getting a free and 40% chance of getting a common card.

At any rare turn, you can get one of these sets:

  • 3 rare
  • 3 epic
  • 3 legendary

I got a legendary about every 10 games and since we have 4 rare+ picks I assume the chance of getting a legendary in a single rare turn is about 2%

I got an epic about every game so I assume the percentage for that is about 20%

TL;DR:

Normal Turn:

  • Free : 60%
  • Common : 40%

Rare Turn:

  • Rare+ : 4 times
  • Epic : 20%
  • Legendary : 2%

I don't have a source for this its all according to my personal experience. These numbers are most likely wrong, but should give the general idea. More data is needed for better estimates.

In a normal arena deck you will have something like this:

  • 15 Free
  • 10 Common
  • 4 Rare
  • 1 Epic/Legendary

Of course if you are lucky you could get 4 legendaries, 10 rares, etc..