What is cursed energy?
Cursed energy is the power source of all jujutsu. It flows from negative human emotions, fear, anger, sadness, hatred. Every living human generates cursed energy, but only jujutsu sorcerers can see and manipulate it.
The more negative emotions a person feels, the more cursed energy they produce. This is why cursed spirits tend to gather in places of suffering, hospitals, schools, and disaster sites.
Cursed techniques
A cursed technique is an innate ability a sorcerer is born with. Think of it like a genetic power, you either have one or you don't. Each technique is unique to the user (with rare exceptions of inherited techniques within families).
Innate techniques cannot be learned or copied. They are hardwired into the sorcerer's body. Extension techniques are advanced applications derived from the base innate technique.
Sorcerer grades
Sorcerers and curses are ranked by grade, from Grade 4 (weakest) to Special Grade (strongest).
Grade 4: Lowest rank, newly awakened sorcerers. Grade 3: Can handle basic curses. Grade 2: Competent sorcerers. Semi-Grade 1: Between Grade 2 and Grade 1. Grade 1: Elite sorcerers, very powerful. Special Grade: The highest classification, beings of immense power like Gojo Satoru and Sukuna.
Domain expansion
A Domain Expansion is the pinnacle of jujutsu. It creates a separate space using a barrier infused with the user's cursed technique. Inside the domain, the user's attacks become a guaranteed hit, they literally cannot miss.
To counter a domain, you can: deploy your own domain (the stronger one wins), use Simple Domain (a defensive technique that neutralizes the sure-hit), or use a domain amplification to nullify the technique.
Reverse cursed technique
Standard cursed energy is negative. Reverse Cursed Technique multiplies negative energy by negative energy to produce positive energy, which can heal. It is extremely difficult to master.
Only a handful of sorcerers can use it: Gojo Satoru, Shoko Ieiri, Sukuna, and Yuta Okkotsu among the known users. It can heal physical injuries but cannot heal cursed technique damage to the soul.
Binding vows
A Binding Vow is a contract a sorcerer makes, either with themselves or with another person. By accepting a restriction, the sorcerer gains increased power in another area.
Example: Revealing your technique to your opponent (giving them information) in exchange for increased power of that technique. The more severe the restriction, the greater the boost.