Guild Wars 2 never required a monthly subscription from players like most MMORPGs, instead requiring a one-time payment for new players. Now that restriction is gone, because Guild Wars 2 is has gone free to play.
The few differences between free and paid accounts are outlined on a FAQ post. Free players get less character slots and are restricted from certain items and chatting options. Some of these options can be unlocked by leveling up in the game.
The upcoming expansion Guild War 2: Heart of Thorns will not be free, as it includes some major content additions. The biggest addition is the game’s first Raid, a difficult ten-player cooperative challenge. ArenaNet are currently selling the expansion in three different packages on their website. The standard edition is $49.99, and deluxe and ultimate editions are available for $74.99 and $99.99 respectively.
Guild Wars 2 is free to play today, and the Heart of Thorns expansion launches on Oct. 23, 2015.