i still am confused, some games which are not on GOG.com and very old from 90s where you dunno who has the rights or whatever, or very rare games i googled and found some pages who call themselves abandonware etc.

are those legal or always illegal?

im not indirectly wanting to ask "yeah can i dl old games for free", but the term abandonware. otherwise i wouldnt have about 150 games here on gog and as retail even more ;).

As far as I see it, it is not really legal but as long as they are not sold anywhere anymore probably no one cares about them and it is ok to download them.
But that is just my opinion I am not into laws etc so I can't say what the legal stuff says about is ;-)

As the owners of abandoned games still retain copyright, distributing them is illegal. The copyrights are just not enforced.

There are games which have had the copyright abandoned. But most games on abandonware sites are simply old and likely to be flying well under the radar as far as the copyright holders are concerned.

Download and don't worry anything released before 2001. If they'll come after you, just tell them you came from the past and you thought the original 14 years granted were still in act.

It's a grey zone. The rights for distribution still remain by the publishers but they don't care at all about these games. So they don't mind if you download such games.
Like an old saw sais: "No plaintiff, no judge."
But I think they start to care about it if you want to make some money with their games by commercially distributing them. Then they also want a piece of the cake. And they have the right to sue you.

If a publisher not officially announces that a game form now on is freeware, you can get problems.

As Abandonia says on their FAQ page, any unauthorized distribution of software is technically illegal. Whether someone or some company will prosecute for this or one's ethical view on the subject is another matter.
For example, the developers behind the games Shadows of Cairn, Vigilance on Talos V, and D-Generation have told me that if I wanted their game I should just go find a download somewhere on the Internet, but since they haven't written freeware licenses for the game, it's still unlawful.

"Abandonware" is an entirely informal term. From a legal standpoint, if a title still has valid copyright (which pretty much all games do; due to the amount of time copyright lasts nowadays, no game currently in existence has had its copyright expire), you are not allowed to freely distribute it. But because abandonware games are by definition either abandoned or neglected by their copyright owners, as jadegiant said, nobody is actually enforcing their copyright (either because they don't care or they don't even know they have the rights to the title).

So yes, they're always illegal. But because there are games that aren't legally available for purchase anymore (there can be a multitude of reasons for this), people still use abandonware sites to acquire such games.

You'll not be prosecuted even for pirating Steam or GOG games anyway, so no biggie. Download anything to your heart's content.

It's not legal.

Will the Copyright holder enforce the copyright? Not likely. Occasionally they do, but when this happens, these games disappear from the websites.

Will you get i trouble? Not likely again. The amount of money presumed lost on these titles is not significant enough for any rights holder to file a legal claim.

Is it hurting the industry? If the games are not available for purchase anywhere, then not really. You're not cheating the creator out of money, and you're not cheating the rights holder out of money.

Should these games be free? Not for me to say. I won't say I've never downloaded an abandonware title. But I will say that if it was offered up for cash, I'd buy it.

No, it is not. It is always illegal. It is piracy where the rights holder do not care. That's not very grey at all.
No,it has not. It is very clear cut. See above.

hey, one thing is abandoned games that are not sold anywhere legally (download them is still illegal) and other is dirty piracy of optimized and improved games that require time, effort and invercion from their developers and companies like GOG!!

This. It's always illegal. But it may not be wrong. the two are not always synonymous.

Technically it may not be legal, but i'm sure a good number of those companies that made some of the older games just don't exist anymore.

Take one of my all time favorites: Xixit, company (Optik Software, Inc.) doesn't exist anymore. No one to enforce copyright. Yeah i wouldn't mind dropping the devs a few dollars assuming i could ever find them.

As such, would it be legal to download and play the game? Don't know. I do know you can't acquire the game except by abandonware/archive sites, although the demo & full version aren't that different, except the demo stops the game for a good 15 seconds to harp on you to buy the game every 3 levels...