(1)故意不履行
债务人故意不履行其应负担的债务。

(2)故意不为
故意但并不一定是恶意地不做法律规定的行为，致使他人的安全得不到应有的保护。

• contract by specialty
• contract carrier
• contract carrier by motor vehicle
• contract clause
• contract consideration
• Contract Disputes Act of 1978
• contract for deed
• contract for hire
• contract for sale
• contract for sale of goods
• contract for sale of land
• contract hauler
• contract implied in fact
• contract implied in law
• contracting officer
• contract in restraint of trade
• Contractio rei alienae animo furandi, est furtum.
• contract labor law
• contract lien
• contract malam in se
• contract mala prohibita
• contract modification
• contract note
• contract not to be performed within a year
• contract not to compete