Per 
Item #: SCP-XXXX
Object Class: Safe
Special Containment Procedures: SCP-XXXX is to be placed on a wooden desk and to be connected to a suitably technologically advanced computer. The computer itself must be constantly plugged into a proper 120 volt power source, that of the average American house plug. This plug should be connected to a backup power source in case of emergency power outage. Between SCP-XXXX and the desk must be an object of any size and appearance made of rubber composites (open cell styrene, butadiene rubber or open cell SBR) with fabric bonded to the upper surface. Under no circumstances is any use of the object to be granted to personnel with a security clearance lower than level 4-XXXX.
Description: SCP-XXXX is a ‘gaming’ computer mouse that appears to track its movement by use of an infrared laser on the bottom of the device. The device has 5 buttons and appears to be right-handed. The main two large buttons appear to be the conventional ‘left’ and ‘right’ click that are present on all mouses, although these buttons appear to be fitted in a style to make the design more compact. The object also has a scroll wheel which can be depressed to use ‘middle’ click, and two buttons with arrows pointing in the opposite directions which appear to change the sensitivity of the object on a computer screen.
When used1, it appears to be a normal laser computer mouse, but when used in conjunction with digital entertainment (“video games”) its anomalous properties become present. It bestows high skill in any “video game” that subjects have tested it on, appearing to be better than human potential. Once the subject arises from the table and lets go of the specimen, a seemingly incurable form of blood poisoning manifests itself stemming on the bottom of the person’s right wrist which only retreats by use of the object. As such, only one subject can ever survive at a time and must be kept using the device at least 30% of the subject's living hours. The current subject2 is to use the device for at least one hour every two. According to previous observations, breach of this procedure will cause death within 24 hours.
If SCP-XXXX is unplugged at any time, the item will kill all of its subjects instantly by blood poisoning, indicating the system is mechanical of some sort. No negative symptoms other than death have been observed so far, but using the device while close to death appears to increase its functionality and awareness of its surroundings, or “gamesense,” up to doubling its effectiveness while 30 minutes from death.
Addendum-XXXX-02/15/2017: The device is retrieved by the Foundation from a home in █████████ in California, reacting to reports surrounding an odd case of blood poisoning. After further field testing, it is concluded that the mouse is the anomalous object. Memory-altering memetic agents used on witnesses █ days later.
Addendum-XXXX-02/23/2017: Subject D-XXXX-CS1 tests the anomalous properties of the object on-site for the first time. Subject dies three days later from blood poisoning, but apparently has reached the highest ranking in the popular first-person shooter Counter-Strike (“Global Elite”) in just those three days’ time.
Addendum-XXXX-03/21/17: The device seems to have basic will. It cannot function on its own, but appears to want to be used, and kill its victims that do not use it. It apparently likes to “live on the edge,” increasing performance based on how close to death you are.
Addendum-XXXX-04/02/17: All experiments cease. Current subject undergoing no more testing, but will need to use the object on a regular basis to survive.
Addendum-XXXX-10/29/17: The current user has reached peak potential in 5 different games. Testing officially ends. Patient is put on XXXX-L5 therapy (continual use of the device for 8 hours a day).
