History – real life v. games
To get historical for a brief moment, Karel Čapek was the first person to actual use the term ‘robot’ which was early in the 20 century and came from a word that means ‘hard work’ or ‘drudgery’, since he envisioned machines taking the place of humans in the hardest and most dangerous forms of work, which humans would surely avoid if they were able to build something to replace them. Computer games, with their long-love of employing the sci-fi genre within them have often promoted robots to a far more significant role as enemies, helpers or even main protagonists.
Computer games have also usurped the envisioned role of robots when it comes to 2 out of the 3 main laws which were created for them by Isaac Asimov (the father or all robots/robotics), which were designed to stop robots from killing humans and instead obey us. Clearly, few games have followed these laws and many would be far less enjoyable if you weren’t allowed to wreak a bit of carnage and destruction on robots who would otherwise have killed you, the player. Many plots have referenced AI robots who then turn against their creators, whether it be any game to have come from the Matrix franchise or the Geth rebelling against their Quarian creators in Mass Effect.
Differing roles of robots
Robots have taken centre stage in games like Megaman or Mechwarrior, where you either play as the robot yourself or are controlling one that acts as your representation in the game. In fact, the line blurs around Mechs, which are really only more advanced versions of a Super Suit which features in other games. It technically becomes a question of whether you’re a human in a robotic suit or just a big AI robot; but this can sometimes be unclear and sometimes it just doesn’t matter for the purposes of the game.
Robots provide some of the main enemies in games such as Too Human or Ratchet & Clank Future: Tools of Destruction but can also be useful allies such as Dog in the Half Life 2 games, whose strength allows Gordon Freeman and Alyx Vance to advance through sections of the games that would otherwise be beyond their own abilities. Note also that an AI such as GlaDOS from Portal has many similarities to characters already mentioned, but she/it is often not considered a robot because of not having a manoeuvrable physical likeness, although in her/its case there is a form seen at the end of the game that represents her/it – this is perhaps another grey area in what is deemed a robot.
Any robot seen in a game will be a collection of mechanical components and most likely computer components (though you could theoretically manufacture a ‘robot’ that includes biological components). There exists currently no real life robot that can approximate to the kind of advanced robot technology normally seen in games, which means countless developers have simply let their creature juices go wild with imagining robots to populate their gameworld; sticking numerous mechanical appendages together, with typically guns or other weapons.
It is expected within games for robots to have superhuman strength, speed, toughness, firepower or a collection of these, which makes them into difficult (or sometimes still not that difficult) foes to face off against or powerful allies.
For similar, but also some different related information, see the Robots concept article.