The Architect is a fictional character appearing in the last two films of the Matrix trilogy, created by the Wachowski brothers. The character is played by Helmut Bakaitis. He also makes an appearance in the MMORPG The Matrix Online. The Architect is first encountered by Neo and appears to be a cold, humorless man sitting in a large circular room whose walls are covered by television monitors in a pivotal scene at the climax of The Matrix Reloaded, the second film of the Trilogy. He never blinks unless he's talking about Trinity to Neo. This is perhaps a trait he takes on to appear more "human" to Neo when he presents Neo with the "choice". He reveals himself to Neo as being the creator of the Matrix.
The Architect is the program that created the Matrix and oversees its function. As a program of the Matrix, he is artificial, but this is much more noticeable than with other programs. Unlike most other programs, the Architect is extremely mechanical in his actions - he speaks in long logical chains of reasoning, utilizing several connectors such as "ergo" and "thus", and has little variance in his tone of voice. He also has little facial expression beyond smirks and glares, but does exhibit emotion on limited occasions, such as regret, annoyance and arrogance. He doesn't even blink unless it's to appear to be more "human".
The Architect's first attempt at a Matrix was a utopia, but it failed miserably and many human lives were lost when the inhabitants refused to accept such a world. The Architect redesigned the Matrix to reflect human history and culture, but it still failed. The solution to this problem was discovered by the Oracle: a version of the Matrix that gave humans the unconscious choice of accepting it. This version was accepted by nearly 99% of all test subjects. So the Matrix was rewritten to allow subjects to subconsciously choose whether or not they wanted to be a part of it. However, the small percentage of humans that did not accept the Matrix would inevitably increase and become a threat to it. Despite this problem, this threat was not unexpected and thus, to some extent, could be controlled, leading to the cycle described in the films.
In the third film, the Oracle explains to Neo that the true purpose of the Architect is to balance the mathematical equations that make up the programming of the Matrix, and he is unable to see the world as anything beyond a series of equations. It is also because of this that he is unable to comprehend choice and free will and cannot see the results of such choices as they are nothing more than variables in an equation to him.
With the new Matrix in place, a system was enacted to control the inhabitants who refused to accept it. While the Oracle was able to guide the actions of the humans who left the Matrix through prophecy, it was the Architect who programmed The One that would fulfill these prophecies. The One was made carrying not only the source code of the Matrix "Prime Program", which gave him his outstanding powers over the Matrix, but also with a profound attachment to humanity that would later motivate him to fulfill the prophecies being spread by the Oracle. Every time the free humans had grown strong enough to start threatening machine hegemony, The One would be born into the Matrix.
As the prophecies were fulfilled by The One, the machines would begin building an army to destroy Zion. Under the guidance of the Oracle, The One would find his way to the machine mainframe, also called The Source, convinced that his actions there would end the war on behalf of the humans. The Architect, however, resides in a room that lies on the path to the Source, so the One would invariably encounter him along the way. During this encounter, The Architect would reveal his influence over the preceding events and the reason the Matrix had been designed to allow a small percentage of its inhabitants to escape. He would then present The One with a choice:
The machinations of The Architect and The Oracle were quite successful in maintaining the status quo, at least initially; until Neo, all incarnations of The One had chosen to cooperate with the Machines in order to preserve humanity in an endless loop of war.
In The Matrix Reloaded, The Architect offered Neo the same choice he offered his five predecessors. He informs Neo that the machine army is going to destroy Zion. Neo can choose to return to the Matrix, or he can return to the Source, choose a few selected humans to restart Zion, and continue the cycle. In the past, the five previous "Ones" saw little choice - an extremely high probability of death for all humanity by refusing to cooperate, or the certainty of keeping humanity alive by returning to the Source. But, unlike previous Ones, Neo was experiencing his programmed attachment to humanity in a specific way: in his love for Trinity. At the same time Neo had met with the Architect, Trinity was in the Matrix being chased by an Agent in a re-enactment of a nightmare Neo had that ended with her death.
Presented with a choice between the destruction of humanity or losing Trinity, Neo saw no choice. His love for her led him to choose to attempt saving her, even though the Architect had asserted that her death was certain and his attempt to save her would mean doom for all humanity.
During their conversation, Neo claims that the machines cannot allow humanity to be destroyed as they are using them for power and thus could not survive if they were killed. In response, the Architect, although his face remained unmoved, stated in a grave voice: "There are levels of survival we are prepared to accept."
The Oracle revealed in The Matrix Revolutions that the summary of the Architect's role in the Matrix was to balance it, like an equation. Furthermore, when Neo asked her what Agent Smith is, she tells him,
"He is you, your opposite, your negative, the result of the equation trying to balance itself out."
When the Architect programmed The One as part of maintaining control over the Matrix, he set the stage for the emergence of Smith as a growing threat against the Matrix and the Machine City. He told Neo that he was, "the eventuality of an anomaly... the anomaly is systemic, creating fluctuations in even the most simplistic equations." These fluctuations appeared to affect Smith, even as Neo destroyed him in The Matrix. In Matrix Reloaded, Smith stated,
"Then you're aware of it... our connection. I don't fully understand how it happened, perhaps some part of you imprinted onto me, something overwritten or copied... You destroyed me, Mr. Anderson. Afterward, I knew the rules, I understood what I was supposed to do... but I didn't. I couldn't. I was compelled to stay... compelled to disobey."
It is unclear whether the Architect directly acted in the interest of balancing Neo within the Matrix, or part of the code inherent to the programming of The One affected Smith. Regardless, the actions of the Architect compelled Smith to go against his original programming and become driven to increase his power like a virus. This directly opposed Neo who was also increasing in strength. As Smith became increasingly angry at the humans and became consumed with the desire to destroy them along with the machines and the Matrix, Neo learned more about the machines and the necessity for their existence alongside humanity.
The threat that Smith represented might have been remedied if the Matrix was rebooted as before, as Neo would die and thus, Smith would no longer be needed. However, it is equally likely that Smith, as an Exile program, could not be deleted directly by the Source (the Machine mainframe) and thus, had Neo chosen to continue the cycle and died, there would have been no-one to stop Smith and his ambitions. But since Neo refused to cooperate with the Architect because of his feelings for Trinity, Smith grew stronger as a consequence, leading to an escalating threat not only to the Matrix but the Machine City also, and ultimately, to the showdown at the end of the trilogy. It is unclear whether The Architect lacked the power to intervene directly against Smith, or if he simply chose not to.
In the final scene of the film The Architect joins the Oracle, commenting that she "played a very dangerous game," referring to the Oracle's role in guiding Neo as he defied the Architect's system of control. The Oracle asks The Architect whether the humans who want out of the Matrix will be released. He says they will and when she asks if he will keep his word he replies, "What do you think I am... human?"