System Sectors (システムエリア, Shisutemu Eria?, lit. "System Area") are locations unique to Kingdom Hearts Re:coded, replacing the Debug Areas that appeared in Kingdom Hearts coded. They can be accessed through Backdoors (バックドア, Bakkudoa?), and are found in almost every world. A System Sector can have several different floors. Once one floor is cleared, a link appears, which allows Data-Sora to move up a floor. Eventually, a terminal will open, allowing Data-Sora to leave the System Sector altogether.
Inside each Sector reside bugs. If a section of the Sector is colored red, bugged enemies must be eliminated. Bugged Heartless are colored completely black with a colored aura and computer monitors floating around them. The color of these auras and monitors indicates some stat boosts that are applied to the enemy:
Once Data-Sora has defeated every bugged Heartless, the room will become blue. The link to move up a floor, or terminal to leave the System Sector, only appears after every room is blue, known as a 'Sector Debug'.
Defeating Heartless and destroying Prize Blox will earn Data-Sora System Points, or SP. Once Data-Sora leaves the Sector, he will be prompted to redeem his SP for rewards. The first few rewards will be highlighted in yellow, meaning that they are "system rewards", and that they can only be redeemed once. Below these are other prizes, which can be obtained repeatedly. Each of these repeatable rewards will double in cost every time they are redeemed. Once the player doesn't have enough SP for an item, they must trade the remainder in for EXP or munny, with the conversion rate varying depending on the sector. The amount of EXP or munny that can be redeemed is capped at 99999.
After completing Traverse Town, System Challenges become available. Once Data-Sora enters a System Sector, he will be rewarded 1000 SP. Before he can enter each floor, he will be prompted to wager 10%, 30%, or 50% of the SP he had when entering the floor. If he can complete the challenge, he will be rewarded the amount wagered, with a multiplier added. If he loses the challenge, he will lose the amount of SP wagered. If the player runs out of HP during a challenge, they lose a large majority of their SP. Each floor has a separate challenge. Later in the game, floors may be randomly infected by a virus (ウイルス, Uirusu?), forcing Data-Sora to wager all of his SP on its challenge, and causing each room to be not only bugged, but have stronger Heartless.
Main Article: Avatar Menu
A special System Sector called the Avatar Sector is available through the Avatar Menu on the title screen. This sector has several differences compared to normal System Sectors:
Obtaining all of the SP rewards in a System Sector often requires a very large amount of SP. The best way of gaining SP is by taking the 50% SP bet and clearing every floor's challenge, which will cause the player's SP to increase at a rapid pace. However, this dependence on the SP multipliers changes how a System Sector should be approached as each floor is cleared.
For the first 3 or 4 floors of a System Sector, gather as many resources as possible - defeat every heartless and break every Prize Blox once in each room (leaving and returning to a room to break the same blox again won't award any additional SP). Make sure to clear out every non-bugged room before clearing the bugged rooms - if the non-bugged rooms are left for later, then there is the possibility that an Eliminator will appear in the room instead. Eliminators are very difficult to defeat and can take away a lot of SP, so they're usually not worth it unless a floor challenge specifically calls for it. Additionally, even if the Eliminator is defeated, the normal enemies in the room will not re-appear afterward, essentially making that SP lost.
After the first few floors, combat should be limited to requirements to clear the floor and challenge, and otherwise should be avoided as much as possible. This is because enemies' damage will take away a scaled amount of SP, and after a few floors of SP multipliers, damage from enemies will start taking away more SP than could be gained by defeating them. The SP given from Prize Blox will similarly start to seem small, so they can be skipped if it isn't safe to approach them.
Each System Sector requires Data-Sora to find a Backdoor, which is invisible, so that he can access the System Sector. While finding a Backdoor, a beeping is heard and a blue sensor appears on the bottom screen, mini-map, around the icon representing Data-Sora. Finding a Backdoor is similar to playing a game of "Hunt the Thimble" as the player must search for the invisible door with the aid of the beeping, which beeps faster when Data-Sora goes closer to the Backdoor, and the sensor, which flashes faster and becomes red when Data-Sora gets closer. When Data-Sora is very close to the Backdoor, the invisible door is locked on and the player must examine it to open the door, making it visible.
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