The gacha system in Genshin Impact is called Wishes and it is used to acquire different characters and more powerful weapons. You will be able to pull on the gacha once you have reached Adventure Rank 5. When you reach Adventure Rank 10 you will have been awarded with enough free summoning material to be able to do two or three pulls on the gacha. It is recommended that when you do decide to summon you use the Beginner’s Wish banner which gives you a 20% discount and guarantees you the 4-star character Noelle on your first 10 pulls.