Guidebook for a game

I'm not a lawyer, so don't take what I say as fact.

It probably doesn't matter, so long as you're not trying to make money off of it. I see a ton of guides/codes/faqs available on Gamefaqs.com, yet that site hasn't been shut down, even though people write a ton of guides for games there (computer or console. The forums there, on the other hand, can get quite childish at times, but that's another issue hehe).

Chances are you probably won't get sued for writing it, but also don't charge money for it (unless you're working for a legitimate game guide publishing company, like Bradygames or Prima) or you could face some legal action.

If you are trying to make money off of it though, yeah, you may want to contact the publisher of the game to try and get those rights (again though, if there is ever a guide made, it's probably already done via Bradygames or Prima, so you're best bet is to contact them and try to get a job there).

I have to say though, sometimes their info is horribly inaccurate (at least when it comes to massive multiplayer online games, or MMO's such as World of Warcraft or Everquest. For those, I'd stick to online sources, as they're more up to date), so make sure you know a lot about that game (although usually the company making the game will tell you stuff so you can put it into the book as well. After all, it's not a very useful guide if the book doesn't tell you how to solve that puzzle in the game lol).

There are unofficial guides, and it's certainly possible to make money from them. The basic deal is this: there's all kinds of stuff that technically, you're not really allowed to do - for instance, a games magazine printing a walkthrough with screenshots is technically breaking copyright rules. But nobody sues over that, so everyone does it.

(Prima and Bradygames do official guides. They're written while the game is in development, often working from beta or work-in-progress builds, updated as the game approaches launch (essential, since that's when they need to be on the shelves).)

As a result, writing something like this means pushing the rules as much as you think they'll go without breaking them. But there are no guarantees that they'll leave you alone, just because you played it safe. Your biggest problems are going to rest with things like trademarks, rather than the actual 'go here, do this' type walkthrough. Really, the best thing to do is see the kind of things that are already around, and haven't drawn lawyer-fire - UHS, IGN, GameFAQs, whatever.

(Although with sites like GameFAQs, and whole fansites dedicated to individual titles, you're going to have to do something pretty damn good to make a go of a commercial walkthrough)