Pirates of the Burning Sea (abbreviated PotBS) is a massively multiplayer online role-playing game (MMORPG) developed by Flying Lab Software (FLS). The game is set in the Caribbean in 1720 and combines tactical ship and swashbuckling combat with an immersive player-driven economy.

Pirates of the Burning Sea has been in development since 2002. During the first few years of development, Flying Lab Software realized that this project required more attention than anticipated. Gradually, not only have they more than doubled their staff, but have also put an MMO entitled Delta Green (based on the role-playing game of the same name), on hold. Beta testing began on 14 December 2005, and ran until 1 January 2008. Pre-release started on January 7, 2008 for players who purchased the pre-order. The retail release date was January 22, 2008. The game is subscription based, and requires a monthly fee to play, except for the first month which is free. It is also included in Sony Online Entertainment`s Station Access, which is a monthly subscription service that provides access to all of SOE`s games for a flat monthly fee. There`s also a 14 days trial that potential players can acquire through PotBS`s website. As the whole game now is legally downloadable for no cost, this makes the game playable for 14 days for free. In April 2008 one time server transfers were added along with the announcement that the original server list was being reduced to 4, in an effort to increase server populations. In November 2008 7 servers were closed for all players and the number reduced to 4. As of March 2009 the six active servers worldwide that are available for new player creation and transfers to are Antigua (North America/World), Blackbeard (North America/World), Rackham (North America/World), Defiant (Australia), Caribbean (Russia) and Roberts (Europe).

Players will choose a Career for their avatars when they begin the game. The Career will determine what abilities and features he will accrue as a captain. The player will receive one point for his avatar`s career on every other level gained. These points can be spent in various ways depending on which career the player has chosen. Once a career is chosen, it cannot be changed. There are a total of 45 skills for each Career. The skill trees are composed of 9 skill chains, each 5 skills in depth. A player will be able to reach the end of a single skill chain by Rank 15, and is then considered somewhat equal to a Rank 50 in that skill chain.

Players in Pirates of the Burning Sea will create up to six characters per server to represent themselves in the game. Each of them will captain their own ship and fight either for a nation of their choice or as a Pirate (see below). As the player moves along in the game, the character will develop by gaining ranks (The equivalent of levels in other MMOs). The player can thus unlock new features, such as fighting abilities, and, most importantly, will be able to captain larger and better ships. The maximum rank a player can reach is 50. When the character is first created, the player chooses a faction to join. This can be any one of either Britain, France, Spain or the Pirates, known as the Brethren of the Coast. The Dutch are also shown throughout the game, but are not playable. A player is restricted to one nation per server, and this choice can only be undone by deleting all of that player`s characters on that server. Each of the four nations will have different starting ports, and therefore access to different resources at the start of the game. This remains somewhat controversial, as while a National character can have any and all classes (Privateer, Naval Officer, Freetrader), a Pirate player is limited solely to pirates on that server, and can only have cross-class `alts` on a separate server. The recent server merge (collapsing servers from 11 to 4, through character transfers) has further complicated the situation as, despite being open to all, different servers cater to different populations and have different peak activity (for example, Roberts is an `EU` server, with high activity during its corresponding time-zone). Only one semi-official European server exists, so the issue remains to be resolved. After a player has chosen a nation, he will be able to customize the looks of his character. These will be alterable in-game and do not affect gameplay directly. There are thousands of different combinations available to the player, who can freely specify each of the 14 different slots. Most items allow color customization to further personalize the avatar`s look. The avatar`s appearance is also based on level; the more impressive and intricate clothing is restricted to higher level characters. Certain items, such as peg legs must be earned through completing missions and some luxury clothing can be bought but are generally pricey.

Swashbuckling is based on a fighter`s ability to manage their opponent`s balance. Each participant has a balance meter, used to determine how capable a character is of parrying, blocking or dodging an attack. Players use "Preparatory Attacks" to lower their opponent`s balance, and then use offensive attacks to deal damage. Players and NPCs alike aim to reduce their opponent`s balance meter while keeping their own at a sufficient level. The player chooses one of three fighting styles, and through gaining ranks, earns swashbuckling points to spend on skills. There are a total of 45 skills for each fighting style. The skill tree is composed of 9 skill chains that are each 5 skills in depth. A player will be able to reach the end of a single skill chain by Rank 15, and is then considered somewhat equal to a Rank 50 in that specific skill chain.