The Karna Parva (Sanskrit: कर्ण पर्व), or the Book of Karna, is the eighth of eighteen books of the Indian Epic Mahabharata. Karna Parva traditionally has 96 chapters. The critical edition of Karna Parv has 69 chapters
Karna Parva describes the appointment of Karna as the third commander-in-chief of the Kaurava alliance. The Parva recites how war begins to tire and frustrate everyone. This book describes how brutal war leads to horrifying behavior over the 16th and 17th day of the 18-day Kurukshetra War. This parva describes deaths of Dushasana, Banasena, Vrishasena, Susharma and finally Karna. At the end of the parva, Karna is killed in a fierce battle with Arjuna.
Karna Parva includes a treatise by Aswatthama which focuses on the motive of the deeds of human life. The crowning incident of this Parva is the final confrontation between Karna and Arjuna, in which Karna is killed.
This Parva (book) traditionally has 96 adhyayas (chapters). The following are the sub-parvas:
After learning of the deceptive way his father was killed, Ashwatthama became filled with wrath and invoked the celestial weapon called the Narayanastra, against the Pandavas. When the weapon was invoked, violent winds began to blow, peals of thunder are heard, and an arrow pierced every Pandava soldier. This had put fear into the Pandava army, but Krishna by stopping the troops advised that the army lay down all its weapons and surrender to the weapon. As himself being the incarnation of Narayana, he knew about the weapon, as the weapon only targets an armed person while ignoring unarmed ones. After getting their soldiers to disarm (including Bhima with some difficulty), the astra passed by harmlessly. Narayanastra failed to harm Arjuna and Krishna as they both were divine persons (Krishna himself is Narayana and Arjuna is Nara). When urged by Duryodhana to use the weapon again, desirous of victory, Aswatthama sadly responded that if the weapon is used again, it would turn on its user. Narayanastra destroyed one Akshauhini of Pandava army completely. After the use of Narayanastra, a terrible war between both armies took place. Ashvatthama defeated Dhrishtadyumna in direct combat, but failed to kill him as Satyaki covered his retreat. On 16th day of war, Karna defeats Satyaki, Nakula, Sahadeva, Bhima but spares their life due to Kunti's vow .
In very early hours, after the sunrise; Trigartas and Samsaptakas engaged fight with Arjuna. Arjuna began to sweep the armies. Arjuna used his Nagastra. Then Partha slew them with his straight arrows. Indeed, all these warriors in that battle, aiming at whom Partha had invoked that foot-tying weapon, had their lower limbs encircled with snakes. Then Susharma countered with his Sauparna astra. Thereupon numerous birds began to come down and devour those snakes. There was no man amongst them that could fight with Arjuna. Arjuna began to destroy all the troops. Beholding that slaughter, all of them remained perfectly inactive, without putting forth their prowess. Arjuna slew all Sampsaptakas and Trigartas. Arjun also killed King Susharma. Arjuna slayed 1,000 warriors. When Arjuna was involved in fight with Samsaptakas, Karna defeated the Pandava brothers Nakula, Sahadeva and Yudhishthira in battle but spared their lives as per promise he made to Kunti. Karna along with his son Vrishasena began slaying armies of Pandavas. Arjuna came into the place where Karna and Vrishasena were creating havocs. He engaged a long duel with Arjuna. The much anticipated battle between Arjuna and Karna took place fiercely. As the battle intensified, Arjuna pushed back Karna's chariot 21 steps backward every time by the energy of the arrows, but Karna could push Arjuna's chariot only 3 steps back. For this, Krishna applauded Karna and not Arjuna. When questioned by Arjuna, Krishna said it is meant to be impossible for any human ever to push his chariot backwards because the chariot of Arjuna contains both Hanuman and Krishna, thus holding the entire weight of the universe. But still, Karna pushed the chariot back and thus, deserved the applaud. Being pushed back by Arjuna, Karna began coming forward but then Karna's chariot wheel was trapped in the mud as a result of the curse he had received earlier from goddess Earth. At the crucial moment, he forgot the incantations to invoke Brahmastra, as a result of his guru Parashurama's curse. Karna got down from his chariot to free the wheel and asked Arjuna to pause, reminding him of the etiquette of war. But Krishna spurred Arjuna to attack Karna reminding the way Karna killed Abhimanyu by stabbing him from behind- which are against the rules of engagement of the war. Being spurred by Krishna, then Arjuna used Anjalikastra to kill Karna which cut the head of Karna, leading to his death. Arjuna had to kill Karna in such a kind of situation only because Karna had banes from Goddess Earth and poor brahmin. Earth Goddess cursed Karna that his chariot wheel gets struck in land which will lead to his death and a brahmin cursed Karna that Karna would die when he is weaponless as Karna killed his cow when it was helpless. In order to fulfill curses, Krishna spurred Arjuna to kill Karna in that situation.  
Karna Parva was composed in Sanskrit. Several translations of the book in English are available. Two translations from the 19th century, now in public domain, are those by Kisari Mohan Ganguli and Manmatha Nath Dutt. The translations vary with each translator's interpretations.
Clay Sanskrit Library has published a 15 volume set of the Mahabharata which includes a translation of Karna Parva by Adam Bowles. This translation is modern and uses an old manuscript of the Epic.
Karna Parva, Chapter 6:
Passion, engagement, skill and policy - these are the means to accomplish objectives.
Karna Parva, Chapter 69:
Many people maintain that morality can be learned from the scriptures alone; I do not find fault with that, but then everything is not provided in the scriptures.
Moral precepts have been made for the well bring of all creatures.
Moral precepts have been made to free the creatures from all injuries.
Dharma - morality - is so called because it protects all. Morality saves all creatures. That is moral that keeps creatures from injuries.
An untruth spoken to save creatures from injuries is in the cause of morality, and does not amount to a falsehood.