One wallet, everywhere
Every ticket you hold is in your wallet — on the website and in the app, under the same account. Buying on your laptop and arriving with your phone is the normal case, not a special one.
The QR code is the ticket
Each ticket carries its own signed QR code. It is the thing that gets scanned, and it admits one person once. Once a code has been scanned, presenting it again — from a screenshot, a forward, or a second device — will be refused.
Before you get to the door
Venues are where phone signal goes to die. Open your ticket while you still have a connection and leave it on screen, and turn your brightness up — a dim screen behind a scratched protector is the most common reason a scan takes three tries.
Gate staff scan with apps that keep working offline, so a dead venue connection on their side is not your problem. A dead connection on yours, with the ticket never opened, is.
Buying for other people
Buying several tickets puts them all in your wallet. You can walk everyone in on your phone, or transfer a ticket to each person so they arrive independently.