For the film:
In the 1960s, a brilliant researcher named David Banner (Nick Nolte) believed that humanity can exceed the limits and the boundaries set by God. In 1966, he wanted approval from General Ross (Sam Elliott) to use his research on experimentation, yet was not given permission to do so. David experimented on himself and fathered a son: Bruce Banner for his early childhood. David was so upset at the military and set off a gamma explosion at his neighborhood.
Thirty years later, Bruce Krenzler (Eric Bana) became a scientist at Berkeley Institute with his childhood friend, Betty Ross (Jennifer Connelly). Krenzler and Betty tested nanomeds on Freddy the frog to minimal success. The day later, Bruce decided to test another frog but the gamma radiation won't stop. Bruce went inside the machine and saw his a green explosion in his eyes. Bruce believed the explosion healed him. Bruce encountered the new janitor who is actually his real father. Bruce did not believe a single word from David.
David took a sample of his son's DNA and tested it on three dogs. Bruce became a giant, green monster whenever he has bursts of rage. Bruce nearly demolished the institute. Betty saw Bruce in her cabin. Bruce got a phone call from his father learning that David took a sample of Bruce's DNA and sent his dogs towards Betty. Bruce became angry again and killed the three dogs. Bruce realized that the nanomeds respond to emotional trauma including anger and repressed memories, which Bruce denied he had.
The next day, Bruce Banner was tranquilized and sent to the San Francisco military base. David Banner tested the radiation on himself with the nanomeds and DNA of his son, which makes him absorb and become a material he touches. Betty Ross decided to talk to David Banner and learned that he intended to kill Bruce but accidentally killed his wife instead. Bruce broke out of the base and became green again while rampaging to San Francisco.
Both Bruce and David were sent to two electric chairs and decided to talk. When the argument heated up, David bit into the cable and absorbed all of the electricity. Bruce became the Hulk again and attacked his father to a lake, where David became a man of stones. In the water, David took Bruce and wanted to get Bruce's energy. Bruce gave in, which made David become a giant, green bubble that later exploded from a gamma missile.
A year later, Bruce Banner decided to stay at South America while hiding his identity.
For the video game:
Eight years later, Bruce Banner returned to America.