Tier 1 level Rarity: 1 in 121 boosters

(Tabard of Flame, Picnic Basket, Goblin Gumbo)

Tier 2 level Rarity: 1 in 242 boosters

(Hippogryph Hatchling, Imp in a Ball, Fishing Chair)

Tier 3 level Rarity: 1 in 484 boosters

(Riding Turtle, Banana Charm, Spectral Tiger Mount)

March of the Legion set is supposed to have increased "drop" rates. UD has yet to confirm the actual rates. For what were seeing there probably 20-30%% better.

At the moment we guestimate:

Tier 1 level Rarity: 1 in 80 boosters

(Paper Airplane)

Tier 2 level Rarity: 1 in 160 boosters

(Rocket Chicken)

Tier 3 level Rarity: 1 in 350 boosters

(Dragon Kite)

Experience

5 cases opened: So far 9 Gobin Gumbo, 5 Gone Fishing, and 1 Tiger. This distribution is over 60 boxes or 1,440 packs.

UD posts

The insertion rates of Loot cards in boosters has not changed since HOA. It was the same in Dark Portal, and will be the same in FOO.
Dan Bojanowski
Sr. Product Manager, WOW TCG

1/3: 1 out every 121
2/3: 1 out of every 242
3/3: 1 out of every 463 or so packs. This number is roughly around 2 cases or 24 boxes