We currently have guest checkout in place, which is perfect for one-time buyers, etc. This feature can be turned on or off depending on your preference.
When a user adds a ticket to their basket, they'll get prompted to either create an account/login ot just place the order if you have guest checkout activated. If you don't have it activated, the place order button will be greyed out till they log in/create an account.
When a user does do guest checkout, they will need to enter their email address for winnings. They will not be able to claim their instant wins unless they register an account with that same email address that they've used.
An account is technically created in the background for them, but they won't be able to see the same things as a usual user would unless they register.