- Mortal Kombat II: "A former Shaolin Monk and a member of the White Lotus society, he is the last descendant of the Great Kung Lao who was defeated by Goro 500 years ago. Realizing the danger of the Outworld menace, he joins Liu Kang in entering Shao Kahn's contest."
- Mortal Kombat 3: "Kung Lao's plan to reform the White Lotus Society comes to a halt when Shao Kahn's invasion takes the earth by storm. As a chosen warrior Kung Lao must use his greatest fighting skills to bring down Shao Kahn's reign of terror."
- Mortal Kombat Gold: "Many believe that Kung Lao had died in injuries suffered during the final fight against Shao Kahn. In fact he had merely turned to a new life without violence in reverence to his ancestral beliefs. As news of Shinnok's threat reaches Kung Lao together with the apparent return of Goro, Kung Lao returns once more to challenge his ancestor's killer."
- Deadly Alliance: "Kung Lao was the first to find the body of his friend and fellow Shaolin monk Liu Kang. He later discovered that it was in fact Shang Tsung who had dealt the fatal blow. Enraged, Kung Lao abandoned his Shaolin beliefs and vowed revenge against the sorcerer. He knew that his fighting skill would not be sufficient to best Shang Tsung. He would need training from the same Outworld master who had taught Liu Kang the one special attack he needed to win the Mortal Kombat tournament so many years ago. Kung Lao traveled to Outworld and informed the martial arts master, Bo' Rai Cho, of Liu Kang's death at the hands of the sorcerer Shang Tsung. Devastated by the news, the old master agreed to teach Kung Lao the flying kick Liu Kang had used to defeat Shang Tsung a decade ago. The training was intense, but Bo' Rai Cho was determined to give Kung Lao a greater edge than he had given Liu Kang. Once Kung Lao had mastered the 'Whirlwind Kick', both he and Bo' Rai Cho journeyed across Outworld to deal with the sorcerer Shang Tsung."
- Shaolin Monks: "The Mortal Kombat tournament was Kung Lao's only opportunity to bring honor to his fallen ancestors. But when he did not receive the approval of the Shaolin to represent them, he disguised himself as a Masked Guard and waited for his moment to strike at the sorcerer Shang Tsung. During the final battle, Kung Lao joined Liu Kang and his new found allies as they did battle against the forces of evil."
Trained in the ways of the Order of Light, Kung Lao is the last known descendant of the Great Kung Lao, a former Champion of Mortal Kombat, who lost the title to Goro 500 years previously, resulting in Lao's death at Goro's hands and the start of Shang Tsung's rule over the tournament. Like his friend Liu Kang, Kung Lao is also a member of the White Lotus Society. Kung Lao was originally the one to represent the Shaolin in the Mortal Kombat tournament but he declined, knowing of the consequences of becoming champion. As a result, Liu Kang was chosen and emerged as the winner.
When the Shaolin Temples were attacked by Baraka and his Tarkatan soldiers, Liu Kang and Kung Lao resolved to travel through the portal to the Outworld and avenge their fallen Shaolin brothers. Although he joined his friend in his furious quest, Kung Lao's ultimate goal was to rebuild the White Lotus Society at the Wu Shi Academy, in order to train a new generation of warriors for the coming ages. He, along with Liu Kang, ventured into Outworld to do battle with Outworld's forces in a new tournament. Following Shao Kahn's defeat at Liu Kang's hand, the monks returned to Earthrealm and began training the next generation of Shaolin warriors. Kung Lao's character bio was not included in the arcade version of Mortal Kombat 3, but was later made available for the home versions.
When Shao Kahn's invasion of Earthrealm came, he had to temporarily scrap his plans for reforming the Society. Eventually, Kung Lao faced Shao Kahn; the Emperor of Outworld blasted Kung Lao with a powerful spell and injured him so badly that he was believed to have died. Hearing of Kung Lao's apparent death enraged Liu Kang, as he challenged Shao Kahn and successfully defeated him for the second time.
With Outworld driven back, Kung Lao decided not to return to the Shaolin Temples, instead allowing everyone to believe that he was dead and went on to live a life of peace in respect to the beliefs of his ancestors. This would not last long however, as he was drawn away from his newfound peace to help fight against Shinnok's forces, when word reached him that Goro, the Shokan warrior who had killed the Great Kung Lao centuries ago, was still alive. After Shinnok's defeat, Kung Lao attacked Goro, who had signed a peace treaty with the Centaur under the mediation of Princess Kitana. Instead of being an attempted assassination, however, the blow was a ceremonial strike of vengeance for the Great Kung Lao's death. With this act, the two warriors shook hands, their feud over.
The next years were peaceful. This ended on a brutal note at the time of Mortal Kombat: Deadly Alliance, when the sorcerers Quan Chi and Shang Tsung united and murdered Liu Kang in a vicious attack (Shang Tsung posing as Kung Lao to get close to the champion). Kung Lao found the body of his longtime friend, and was told immediately by Raiden that Shang Tsung was the assassin, who had formed the Deadly Alliance with Quan Chi. Enraged, Kung Lao vowed revenge upon the sorcerer, and once again abandoned his pacifist Shaolin beliefs. He believed his current skills were insufficient to defeat Shang Tsung. So after meeting with the other Earthrealm warriors and traveling to Outworld, Kung Lao sought the advice of the martial arts teacher Bo' Rai Cho. Bo' Rai Cho trained Kung Lao for a short time, teaching him the 'Whirlwind Kick' maneuver. Together, they joined the other warriors in the assault against the two sorcerers. Kung Lao would not rest until Liu Kang was avenged, and Shang Tsung had paid with his life. He then invited Bo' Rai Cho to join him in going back to Earthrealm and train more warriors at the Wu Shi Academy.
The assault against the sorcerers did not end well. With Liu Kang dead, Raiden and his companions were fighting a losing battle. Kung Lao and Kitana challenged the Deadly Alliance, with Kung Lao battling Shang Tsung one on one. Despite his improved skills, Lao's strength was inadequate in comparison to Tsung's, which resulted in his death. Furthermore, Kitana died at the hands of Quan Chi, leaving Raiden alone to battle the Deadly Alliance. However, Kung Lao was revived by Onaga as a servant during the events of Deception. Ermac's Deception ending, which shows him and Liu Kang's spirit being successful in rescuing the enslaved Earthrealm warriors, is generally accepted as the possible explanation of how Kung Lao was freed from Onaga's spell.
Fujin's bio for Mortal Kombat: Armageddon describes Kung Lao as having joined forces with the him in order to bring their former comrades Raiden and Liu Kang under control, with the God of Thunder becoming "as ruthless as Shao Kahn" and Liu Kang's corpse selectively slaying various people. Fujin then goes on to state in his bio that if no way was found to revert the two corrupted warriors back to normal, both he and Kung Lao would be forced to finish them.
- Mortal Kombat II (Non-Canonical): "A former Shaolin monk alongside Liu Kang, Kung Lao also grieves the loss of their Shaolin brothers. He realizes that his ultimate fate lies in the dark realm of the Outworld. He defeats his Outworld opponents until he emerges the supreme champion. With his strength and spirit in complete alignment, he finally avenges the death of his great ancestor. Although his greatest challenge lies ahead."
- Mortal Kombat 3 (Semi-Canonical): "When Kahn invades Earth, Kung Lao must scrap his plans of reuniting the White Lotus Society. He instead must focus on the new tournament. He seeks Liu Kang and together, they battle Kahn's forces fearlessly. Using the knowledge he obtained as a Shaolin monk, he fights in the name of his great ancestor- The Original Kung Lao. He emerges victorious, but suffers from injuries during his battle with Kahn. Believed to have passed away, Kung Lao joins his ancestor in a new life."
- Mortal Kombat Gold (Canonical):
- (In the Kuatan Palace, Goro is looking out the window)
- Kitana: Goro. (he turns to see her, coming along with two Edenian guards) We are here to offer the Shokan a treaty for truce. The Centaurs have already signed and agreed to all terms. We now await your acceptance.
- Goro: War has been waged in this realm for too long. We must bring it to an end. I will set aside my differences with the Centaurs, as long as they abide by the treaty. (uneasily) I shall sign your agreement.
- Kitana: Goro, this is a great victory. For all of us. (reaches out for him)
- (suddenly, Goro is struck down by a razor hat. Kitana dodges it when it comes back, and Kung Lao, from a beam up high, catches it)
- Kitana: Kung Lao! We are at a moment of peace! How could you attack now?
- (Kung Lao jumps down)
- Kung Lao: I once thought that an allegiance with an enemy was a lost cause, Princess Kitana.
- Goro: (stands up with a scar across his chest) Was that your attempt of an assassination, Earth man? (walks towards Kung Lao, menacingly)
- Kung Lao: No. That was a ceremonial strike of revenge, for my ancestor that you killed in Mortal Kombat, so many years ago.
- Goro: And do you wish to continue this battle?
- Kung Lao: No. (takes off his hat) I wish only to settle the differences between us.
- Goro: Your ancestor was a great man. A brave and noble warrior. You should be proud of his accomplishments. If he won, perhaps it would be my own son seeking to settle differences with him.
- (Kung Lao offers his hand, which Goro shakes symbolically)
- (In the Kuatan Palace, Goro is looking out the window)
- Deadly Alliance (Non-Canonical): "Rage fueled Kung Lao's thirst for revenge. The memory of holding his fellow monk's broken body on the lei tai of the Wu Shi Academy grounds consumed him as he rained blow after blow down upon Shang Tsung. Kung Lao had finally mastered the attack Bo' Rai Cho had taught him. The sorcerer could not withstand his whirlwind assault. Shang Tsung begged for mercy. Kung Lao granted him none. Upon his return to Earthrealm, Kung Lao stood before the modest shrine to Liu Kang which had been erected by the Wu Shi initiates during his absence in Outworld. He lit a stick of incense and placed it among the others already burning there. He bowed his head and prayed for safe passage to the afterlife for his friend and brother. With Shang Tsung's death, Liu Kang's spirit could rest peacefully. Earthrealm was safe once more, but at terrible cost. The work of the White Lotus society had become more important than ever."
- Armageddon (Non-Canonical): "The power released by his victory over Blaze opened a portal, and Kung Lao found himself in Earthrealm hundreds of years in the past. His ancestor allowed him to enter the Mortal Kombat tournament in his stead. Kung Lao defeated Goro and won the tournament, becoming a legend. As a result, Liu Kang never competed, and Kung Lao's rivalry with him never came to be."