The story of Phantasy Star Online 2 takes place in the year 283 of the New Light. The space fleet Oracle travels between worlds, with the organization known as ARKS acting as the fleet's vanguards, who were once a team of researchers. Upon discovery of the Darkers, however, they began to use what they knew to develop photon weaponry to combat the coming darkness.
When playing Phantasy Star Online 2, players will always find themselves in the main lobby when first logging on. Split into two sections, the gate area is where players may accept quests and head to the campship, while the shopping area is where a number of different shops may be found. There are also a number of clients and other non-player characters who can be found across both areas. There is also a casino which can be accessed from the back of the gate area, or near the stairs in the shopping lobby; the casino also has a quest counter.
There are three elevators which can be used to transport players between the two areas, and there are also block-changers which dot the edges of both areas. By entering one, players may switch between the blocks, each named for its use, or also head over to their room if they so choose.
The combat system in Phantasy Star Online 2 is action-based, more so than the past games. Players are able to switch between up to six weapon palettes and subpalettes, each of which can be set up to have its own set of Photon Arts, Techniques, items, and so on.
All weapons are capable of a basic attack that will restore PP much faster than normal on contact with the enemy; some weapons have a very short range, while others reach much further. Performing a Photon Art or Technique will consume an amount of PP, though they are far more powerful than regular attacks. Each weapon also has a weapon action assigned to it; some melee weapons will guard, most ranged and technique weapons will switch over to a set of two extra Photon Arts or Techniques, Fighter weapons will perform an evasive action, Twin Machineguns will perform a stylish roll, Dual Blades will glide forward, and Jet Boots will cause a number of effects based on when it is used.
While a default set of controls is presented upon starting the game, they are fully customizable, so any input can be set to do anything the player wishes.
Throughout Phantasy Star Online 2, there are currently five planets for players to visit, each with its own set of fields and creatures; there are also some quests which take ARKS to special areas not located on planets.
Planet Naberius, named for a Marquis of Hell (alternatively known as Cerberus), is a lush, green world which also serves as the training ground for new ARKS members. It also houses vast bodies of water, and an atmosphere which seems quite similar to that of Earth itself. Natives of all shapes and sizes roam the planet.
A craggy, volcanic world with an incredibly hot atmosphere, this planet derives its name from King Amdusias, a demon said to have a voice like thunder. The second world players are granted permission to access, this world seems far more dangerous than Naberius. It is home to the Dragonkin.
This planet, unlike the first two, does not appear to be named for a demon; rather, it seems to be based on the Kingdom of Lilliput from Gulliver's Travels. The kingdom is home to small people, whom the tribe of Lillipans which the ARKS meet on the barren world may have drawn inspiration from. Their Mechs run rampant all over the planet.
Alternatively translated as Wopal, this watery planet has very little solid ground, much of which is actually sandy coasts. Aquatic Oceanids who behave differently depending on the current time of day will attack anyone who comes to their world.
A civilized planet home to two types of Titans, it is currently engaged in a violent civil war which the ARKS tried to stay out of. But once the Kuronites aligned themselves with the Darkers, it was inevitable for the Oracle's fleet to join in.
Based on its real-life counterpart, the year is designated as 2028. After a freak accident caused a dimensional rift to open up, Phantoms have begun to terrorize the streets and ARKS are now capable of hopping between dimensions.
These are locations which are not located on a specific planet, but rather on ships of the ARKS fleet.
Used for training by skilled ARKS members, these locations consist of special challenges to overcome.
There are currently only two fields which fit under this category, for neither exist in a specific location. The Darker's Den is a rift in space where many Darkers are born. There is also Double's Inner Universe, which exists within Dark Falz Double.