The first game featuring Baek Doo San, he is a sub-boss for Marshall Law. Baek accidentally killed his father in a sparring session which made him doubt his own skills. This made Baek go on a rampage and destroy many dojos. One of those dojos belonged to Marshall law. Baek left a note for Marshall Law telling Marshall to meet him at the King of Iron Fist Tournament 2. The two fought and Baek was defeated by Marshall.
Baek's ending in Tekken 2 features him looking at a locket of him and his father. Baek reminisces about the times he was training with his father. Baek forgives himself for killing his father and finds inner peace within himself.
Baek is presumed dead by Hwoarang. It was thought to be the work of Ogre.
Baek's fight with Ogre had left Baek in a coma which he stayed in for a year. After he awoke he began teaching Tae Kwon Do at military bases in Korea. It is there where Baek reunited with his student Hwoarang and they both began training for the King of Iron Fist 5 tournament. Baek ends up withdrawing from the King of Iron Fist 5 tournament when he learns that Hwoarang was seriously injured by Devil Jin.
Baek's ending in Tekken 5 features Hwoarang ready to fight three men until Baek arrives. Hwoarang, distracted by Baek's arrival gets sucker kicked in the head by one of the men he was about to fight. Baek then defeats all three men with ease and then drags Hwoarang away.
Baek entered The King of Iron Fist Tournament 5 with his student, Hwoarang. However, once Baek found out that Hwoarang was defeated by Devil Jin and seriously injured, Baek withdrew from the tournament. Baek rushed to the hospital to visit Hwoarang to find that Hwoarang could not wake up, and Baek blamed himself for not being a better teacher. After several days however, Hwoarang regained consciousness and they immediately discussed the details of the battle. Hwoarang told Baek that he not only has to recover, but he immediately wants to begin training to become stronger.
Upon their return to Korea, Baek and Hwoarang train intensely, and Baek teaches Hwoarang all he knows. Its not long before the announcement of The King of Iron Fist Tournament 6, and Baek decides to enter the tournament one last time.
For his ending, Baek thinks back to youth with his father training in taekwondo all the way up to the horrific accident that killed his father. An almost out of earshot Hwoarang attempts to lighten up his master by mentioning he has been shirking training by oversleeping. But then, Baek regains his senses and commands Hwoarang to do pushups for being late.