http://www.nintendolife.com/news/2015/01/xenoblade_chronicles_x_is_so_sizeable_that_it_almost_needed_more_than_one_disc

Not far off 25GB, then

With the release of Xenoblade Chronicles X just a few months away in Japan, the official social network accounts for the game are revealing more details; an interesting update now relates to the file size of the game.

Other recent details have highlighted the sheer size of the game world, which has a non-linear approach and is apparently five times larger than the huge landscapes of Xenoblade Chronicles. Generating that world, and all of the rules and programming that makes it function, can lead to enormous file sizes - some open world games on rival systems can be particularly sizeable; Monolith Soft's title is no different.

Producer Shingo Kawabata has explained, in recent posts on Twitter, that the new title was almost so big that it'd need an additional Wii U disc.

Xenoblade Chronicles X is using up most of the space on the Wii U disk. It's really, really close to the storage limit. (To the point that at one stage we were considering using more than one disk for the game). To enjoy playing, the enormous seamless map must load quickly (which was achieved through the hard work of our programming division), but we had help from Nintendo proper implementing a further improvement to what we had. I believe we're going to reveal the details of that on the official page in the future, but to people considering purchasing the packaged version of the game, as one of the game's developers, I highly recommend you make use of this improvement.

The bespoke Wii U optical discs are 25GB in size, so based on the comments above we can expect the eShop version to be above 20GB. It's worth noting that Monolith Soft would have been under pressure to make the game a reasonable size to fit on a disc - unlike rival systems the Wii U doesn't typically run a game both from a disc and pre-ordained installed data. The 8GB unit is a clear reason, as mandatory installs would potentially rule out some Wii U owners; that's a theory, in any case.

Regardless, it's clear that Xenoblade Chronicles X is going to be a massive experience on Wii U - if it is truly 300 hours long, as has been claimed, we'll certainly get the most out of every megabyte of data.

Making 50GB discs for the Wii U was the smartest thing Nintendo has done this generation.

Wow! That is going to be epic!!! Dat Digital Download space though

Did Nintendo not have the foresight to make sure their proprietary Blu-ray format can do dual layered so it could reach 50GB? Xbox 360 is the only modern console that still releases games on multiple discs. Thank heaven that PlayStation 3 made Blu-ray a standard format going forward so we don't have to deal with that issue ever again.

Wtf? Why are they saying it's 25GB? Isn't it 50GB?

I thought the WiiU supported dual layered discs?

Makes you LOL at Wii U's storage capacity.

This will probably trigger a lot of people to finally buy an SD card or HDD for their console.

They're 25GB per layer, like Blurays

Why?
Its not like everyone wants to pay way to much for overpriced built in harddrives.

I am more than happy with something like this:


or with my NAS thats sitting next to my router.

I think it's going to be 50GB, not 25GB, judging from this.