Odds
Some things on the island are random: you don't choose which item you get. This page shows your chance of getting each one, before you buy.
Every number here comes straight from the game's server, from the same code and lists the draws themselves use, so it is always up to date. Credits can be bought with real money, so we show the odds of everything random, whether it is paid for in credits or in gems.
Everything else in the Store is never random: a single item, a set, a hypermood, a pet or a whole collection gives exactly what its listing shows (a pet's abilities are below).
Store draws
A collection's draw in the Store - in credits, or in gems for furniture - gives a number of different items of that collection, picked at random. Any item of it can come, and one draw never gives the same item twice. Buying several booster packs at once is the same as buying them one after another, and a draw's price never changes its odds.
Surprise boxes
A surprise box gives one prize, picked at random from its list. Every place in the list is as likely as another, so a prize that is in the list twice is twice as likely.
Pets' abilities
When a pet comes to you - bought in the Store, won or traded - each of its free ability slots gets an ability picked at random from the ones its rarity allows, each one as likely as another, and never one it already has. A slot it gets later is filled the same way. With an Animal upgrade token you can then change an ability to the one you choose.