Word robot first appeared as early as in the 1920s science fiction play, R. U. R (Rustrom’s Universal Robots), by Czech playwright Karel Čapek (1890 – 1938), wherein the automatons featured within the story are not mechanical humans, but synthetic ones created from various organic materials to then serve as workers, hence robot stemming ultimately from robota, “forced labour” – underlining their sense as artificially created slaves.
In 1925 we see in the story City of No Escape by French-English author Thomas Charles Bridges (1868 – 1944), one of the first instances of metallic robots versus what in our contemporary age would be termed synths or synthoids – as made popular by the Fall Out series of role-playing games.
From then on the word became more and more associated with these entities of nuts and bolts rather than the bionic people of the first stories. Science fiction luminary, American author Isaac Asimov [https://sf-encyclopedia.com/entry/asimov_isaac] (1920 – 1992) finally cemented this with his iconic I, Robot (1950) anthology along with the “Three Laws of Robotics”, that – due to editorial needs rather than necessarily personal ones – outlined the hardwired directives of the metal folk.
The word robot can be translated in several ways in Japanese, but the most common is a loan from English, robotto (ロボット) literally rendering the word into the phonetic Katakana syllaberies.
Other words such as jinzou ningen (人造人間, lit. “artificial humans” or “man-made humans”) cover more strongly androids as they are less in the sense metallic and more organic. Kikai ningen (機械人間, “Machine Human”) translates robot entirely and was also part of the vocabulary of the very first Japanese science fiction stories written natively, such as in 1948 with Juuza Unno (海野 十三, 1897 – 1949) ’s Chouningen Ekkusu Gou (超人間Ｘ号, “Superhuman X”), even at times applied with the non-standard reading of robotto, thus giving the Japanese readers the chance to get the meaning of the word literally as “mechanical humans” – even jinzou ningen got this treatment as early as 1931 in Funeraru Mâchi (葬送行進曲) by famed novellist Koudou Nomura (野村 胡堂, 1882 – 1963), where this word is given robotto as its reading.
Cyborgs on the other hand are either saibôgu(サイボーグ, “cyborg”) from English, or kaizou ningen(改造人間, “Modified Human”), the latter appears famously within the manga Cyborg 009 (1964)by the prolific manga author Shoutarou Ishinomori (石ノ森章太郎, 1938 – 1998), though the title itself uses the English loan word – which as with robotto, appears outfitted at times with saibôgu as a reading.
Returning to modern games, the Synths within the Fall Out series of games have their name translated using jinzou ningen, rather than shinzu (シンズ), which would be a possible phonetic rendering of it into katakana – which is the typical fare for loan words.
We will return to how exactly these video game terms are translated into Japanese at a later point.
Overall, another term that appeared during the 1930s and 1940s was kikaijin (機械人 "Machine Person"), which whilst fitting with Isaac Asimov's idea of "mechanical men", was earliest used in Sanjugo Naoki (直木 三十五, 1891 - 1934)'s Robotto no Beddo no Juuryou (ロボットとベッドの重量, The Robot and the Weight of the Bed") from 1931.
There is therefore a varied field of words to use when translating the term and even then each series has its old particular nomenclature for its artificial beings such as the Rock Man X games and their reploids, literally in Japanese Repurioido (レプリロイド) from "Replicant" and "Android." Replicant again a rather popular term for the artificial humans from the classical novel by American author Phillip K. Dick (1928 - 1982), Do Androids Dream of Electric, and the later Blade Runner films, which adapted the story.