Harry Potter: Wizards Unite was due to roll out across the UK and US today (Friday 21st June) but players noticed on Thursday that the game is already available on iOS and Android.
The long-awaited app is made by Niantic, makers of Pokemon Go which revolutionised AR gameplay in 2016.
Characters and creatures from the wizarding world appear in real life on a user’s smartphone, using augmented reality technology.
Developers of the game will want to avoid server issues that affected Pokemon Go when it first launched, as they struggled to cope with the influx of users trying to play it.
Pokemon Go also caused controversy when hundreds of players descended on locations including police stations and churches in search of Pokemon characters they wanted to collect.
Warnings were issued by police to players around the world after reports of gamers placing themselves in danger as they chased the virtual creatures, urging users not to enter dangerous or restricted areas while they played.
The game was a stunning success, however, being downloaded more than 10 million times in its first week and breaking numerous app store download records in the process.