Video games often have a reputation for being juvenile, thoughtless entertainment for children.
Well, much like any other entertainment medium, there are a wide variety of video games; some are indeed brainless entertainment, but others use literature as a jumping off point to explore deeply complicated political ideas.
From Ayn Rand to the Ming dynasty, here are six video games you probably didn’t realise were based on books.
'The Witcher 3' is one of the most celebrated open-world action games in the last decade, but not many people know it's actually based on a series of fantasy novels by the same name.
'The Witcher' series, by Polish author Andrzej Sapkowski, focuses on Geralt of Rivia, a monster hunter who uses a variety of supernatural abilities to stalk his prey.
Unlike the books, however, the video game series allows players to make decisions on behalf of Geralt, shaping the world witch each choice they make.
The series is such a point of national pride for Poland as a whole that its former prime minister gave a copy of 'The Witcher 2: Assassins of Kings' to President Obama as a gift back in 2011.
16th century Chinese literature might not strike you as the best jumping off point for a post-apocalyptic action video game, but 2010's 'Enslaved: Odyssey to the West,' available for the Xbox 360 and PlayStation 3, is actually a modern re-interpretation of 'Journey to the West.'
'Journey to the West,' a Chinese novel that dates back to the Ming dynasty, centres around Xuanzang (sometimes called 'Tripitaka' in English translations), a relatively helpless monk who enlists the help of others to help him on his journey.
One such person is the Monkey King, a mischievous but highly capable warrior.
In 'Enslaved: Odyssey to the West,' Tripitaka becomes Trip, a young woman who forces the game's main playable hero, Monkey, to help her travel across the ruins of what was once New York City.
How does a young woman force a giant, burly warrior to help her, you may ask? She places a mechanical slave headband on Monkey, which causes him pain if he doesn't abide by Trip's orders, and will instantly kill him if Trip is harmed.
That's based on a similar headband that the Monkey King character in 'Journey to the West' wears, which can be tightened if anyone chants a specific mantra to keep his mischievous behaviour in check.
'Journey to the West,' however, doesn't have the voice talents of Andy Serkis or that weird, existential sci-fi twist at the end.
One of the main lines at the heart of the Slovenian novel 'Alamut' published in 1938 is, 'Nothing is an absolute reality, all is permitted.'
Players of the 'Assassin's Creed' series might recognise that as being nearly identical to a line that pops up throughout the franchise: 'Nothing is true, everything is permitted.'
Though not a direct adaptation of 'Alamut,' the first 'Assassin's Creed' contains many similar themes, including criticisms of the way fascistic leaders of radicalized groups manipulate people into their ranks.
If you're looking to dig into the relationship between 'Alamut' and 'Assassin's Creed' more, Michelle Ehrhardt's article on Kill Screen is an excellent read.
Though video games are often criticised -- and rightly so -- for glorifying violence, there are several games that analyse and critique these norms, too.
One such game is 'Spec Ops: The Line,' available for PlayStation 3 and Xbox 360, which explores the muddled and grey morality of war using the novel 'Heart of Darkness' as a major reference point. Much like how 'Apocalypse Now' re-interpreted the book's events to take place in the Vietnam War, 'Spec Ops: The Line' places the story in the Middle East.
The game's main villain is John Konrad, a combination of the names Joseph Conrad, the author of 'Heart of Darkness,' and Kurtz, the book's main antagonist.
As you play through the game, the main character's mental state slowly starts to degrade, and you'll see the toll that war takes on him, both mentally and physically.
'Metro 2033' was initially available for the Xbox 360 and PC, but you can actually play the game and its sequel on PlayStation 4, Xbox One, or PC by buying the 'Metro Redux Bundle.'
'Metro 2033' is a direct adaptation of the Russian novel of the same name. The book was hugely popular in Russia upon its release in 2005, but never enjoyed quite the same fame in the US.
However, its 2010 video game adaptation does the original story justice, mostly because the book's author, Dmitry Glukhovsky, worked closely with the game's developers the entire way through.
In an interview with VentureBeat, he said, 'Somebody asked me if I feel that having my book turned into a video game somehow degrades it. Bullshit. It promotes it, gives it a huge additional audience, and basically just lures teenagers into reading. I say, turn ('Crime and Punishment') into a PC game!'
'Bioshock' isn't so much based on a book as it is a complete takedown of the philosophies in Ayn Rand's written works.
In her writing, Rand advocates for 'Objectivism,' a political/economic/social system in which nobody owes another person anything at all and is free to pursue their own interests, but is also entirely responsible for their own well-being.
As this excellent blog post on Giant Bomb explains, 'the creators of ('BioShock') primarily use the game to explore a single question that Rand takes for granted in her fiction and in her philosophy: 'What would a society look like if everyone were really only in it for themselves and owed no allegiance to anyone but themselves?''
Essentially, 'Bioshock' imagines a world actually based on these ideas and takes them to the extreme as a way of critiquing their flaws.