What constitutes an "open world" game?

skyrim, watch dogs, sleeping dogs and gta v would fall under open world game id say any game that give you more freedom to explore not tide down to mission after mission like say call of duty or halo

coleisme pretty much hit the nail on the head. Open world games emphasize exploration and generally allow the player to choose which part of the world they wish to visit and when. Open world games certainly can have segments of the game world locked off for reasons of progression but the bulk of it should be open for exploration at all times and the player should be able to revisit locations that they have previously been to.

Deus Ex HR is not open world:
Open World usually means that your expirience does not follow a predestined path. For example:

Not Open world: you start at point A, and to get to point C, you need to go through point B. There can be multiple ways to archive B, but it is a requirement to reach C.

Open world: You start at point A, and you can get to point B,C,D,E,F,G in any order, but to get to point H, you need to have at least one of the previous points.


This can take multiple combinations.
The more combinations it gets, the more "open" the world feels.

There are games like GTA as mentioned above that have almost every area open from the start.
There are games like Stalker, where you get maybe 60% of the areas opened, but to get to the rest, you do need to follow a certain path at some point.
An extreme example of open world would be as mentioned before Skyrim, fallout 3, fallout 2, Oblivion, etc.

An extreme example of non open is definitely call of duty.

Usually open world games have more replay ability potential than non open world.

I'd call DE:HR or Thief more player driven, like the Witcher 2, but they're not fully open world. Yes, they both offer small sandbox areas, but ultimately the game still locks you into events and cuts out parts of the game when it wants the story to move forward. A big determining factor to whether a game is open world is if it cuts out areas you've already cleared, or leaves them open to revisit for no reason.

Games like Dark Souls or Overlord: Raising Hell fall right on the edge of this, but since they only get bigger as the game progresses and don't close off any past areas, I'd say they fall on the open world side.

Ofc, 'full' open world games include titles like Skyrim, Minecraft, or Sacred 2.

People tend to think full open world is better, but I'm not sure I agree. There are positive sides to the balance of freedom and focus that games like DE:HR or Dark Souls provide. They balance open gameplay with linearity, ensuring detail and unique content remains amazing, without railroading them down a tiny path or sacrificing exploration. If you look at Skyrim (not one of my favorite games) most of the content is copy-pasted dozens of times, if not hundreds. If you look at Dark Souls, for example, it keeps most of the sense of exploration but with a much higher density of unique content. That's why semi-open, semi-linear games like DE:HR, Dark Souls, Dishonored, or Dragon Age Origins feel more like a real adventure to me than games like Skyrim; you can still mostly go where you want, but without running through the same copy-pasted ruin 10000 times.

Some people call open world games more realistic... Also, not really true. There's nothing realistic about walking through a town made of the same 3 people copied over and over again with slightly different faces (sorry, picking on Skyrim again). I much prefer the system used in Demon's Souls/Dark Souls/Dark Souls 2, where in each game there are probably only ~15 NPCs, but they move about the open landscape, all uniquely voiced and uniquely written, adventuring or settling based on their own goals, personalities, and histories.

And when characters die in Dark Souls (if they die), they're dead. No getting them back, no reloading a save, sorry, you just lost the only high-level blacksmith in the game. That's realism. Not seeing "Jarl Balgruuf is Unconscious" on your screen and knowing that any second the psychic respawning guards will teleport through the doors to attempt an arrest (unless you hit f12 to undo the last 5 minutes).

Weeeeell... I guess I sort of turned that into a list of ways I think Dark Souls is better than Skyrim, rather than just an answer to what constitutes an open world game. o_o