Open-world games
What open world actually means, why it is a structure rather than a genre, and its trade-offs.
An open-world game gives you a large, continuous space you can move through freely, rather than a series of separate levels loaded one at a time. You choose where to go and, usually, what order to do things in.
It is worth being clear that open world is not a genre. It is a structure. You can have an open-world RPG, an open-world racing game, an open-world horror game. It tells you about the shape of the game, not what you do in it.
What usually comes with it
Freedom of movement across a connected map.
Side content — optional activities alongside the main story.
Systems that interact — weather, time of day, wildlife, factions.
Length. Open-world games are usually long, often the longest thing on your shelf.
What are the biggest open-world games?
Grand Theft Auto, The Witcher 3, Red Dead Redemption 2, Skyrim, Breath of the Wild and Tears of the Kingdom, Elden Ring, Assassin''s Creed, Horizon, Cyberpunk 2077.
The honest trade-offs
In favour: freedom, discovery, and the feeling of a place that exists rather than a corridor you are pushed through. At their best these games produce moments no designer scripted.
Against: open worlds can be padded. A map covered in icons can turn into a checklist, and repetitive side activities can dilute a good game into a long one. There is also real fatigue among players who have finished several and recognise the pattern.
The distinction worth making is between an open world with things to find and an open world with tasks to complete. The first is exploration; the second is work.
Before you buy
Consider the time honestly. An open-world game asks for tens of hours, and buying two at once usually means finishing neither.
Also check whether the map is dense or sparse. A smaller world with something interesting every few minutes is usually a better experience than a vast one you spend the time travelling across.