If your not making money and its a fan game not a remake it's in my opnion legal. One fan game doing this is mushroom knigdom fusion. http://www.youtube.com/watch?v=WpBVHQ1XHcU&feature=related

Duke Nukem: Reloaded On the heals of Black Mesa: Source just got full go ahead from Gearbox... and previously 3D Realms had no issue publically about the remake... this is using 100% original assets nothing from the original game at all except i think sound files... then again there all free on the Internet...

Unreal Tournament 2 is a competitive multiplayer science fiction themed FPS where the players fight each other to the death in a futuristic sport. It is made with the Unreal 2 engine.

Killing Floor is co-op survival horror FPS where you must contain an outbreak of monstrous specimens from causing any further murder and mayhem. It is made as a modification to the Unreal 2 engine.

None of the story, characters, weapons, items or levels of Killing Floor are in any shape or form are taken, inspired by or copied from Unreal Tournament 2. This makes Killing Floor a mod.

Half-life is a single Player FPS made in the GoldSrc engine where you play the role of Gordon Freeman, a scientist who must escape from the Black Mesa facility when an experiment goes terribly wrong and monstrous aliens starting invading.

Black Mesa (Previously known as Black Mesa:Source) is a single Player FPS made in the Source engine where you play the role of Gordon Freeman, a scientist who must escape from the Black Mesa facility when an experiment goes terribly wrong and monstrous aliens starting invading.

All of the story, characters, weapons, items and levels of Black Mesa are entirely taken, inspired by and copied from Half-Life. This is why Black Mesa is a fan game.

Both games are made using engines that the developers have specifically designed to be used for modification by the public. If Epic Games all of a sudden said "Hey! Killing Floor is in violation of our IP. Remove it from your servers or we will take legal action." I imagine they would have no legal right to do so. If Valve said the exact same thing about Black Mesa, I would imagine they would very much have every legal right to do so.

That is pretty much what I have been saying to that other guy. So why are you telling me? lol

No, that's what -I've- been saying, that Killing Floor is a mod, not a fangame, as it is not based off any existing IP. Fangames don't have to be mods of existing games, in fact fangames don't have to be based off existing games at all, just existing IP.

Would you call this a mod - http://www.hansoloadventures.com/ ?

Do you need to load Unreal 2 to play it? If no then it's not a mod, it's a game that uses the same engine.
Sorry but using an engine doesn't make it a mod or else pretty much any game out there would be a mod. Mass effect2? unreal3 engine, Gears of war? unreal3 engine. Anything by valve? source engine. How about Star wars: the old republic? is that a mod? I mean it's built on the HERO engine which wasn't made by Bioware by what your saying it's a mod...
The engine is an SDK not a game what you create with these is games, just sharing an SDK doesn't mean that you can just switch out it's exe with the generic one and it will work.

Black Mesa is a fan remake in the source engine it would be illegal to sell or make available without Valves permission. Valve can however remove their permission at any time and issue a DMCA order if it's hosted in the US and a copyright violation notice anywhere in the world.

Original fan games fall foul of copyright too settings etc are copywritable

I think we're just confusing the issue now. Killing Floor started life as a mod. It's now a standalone release in its own right. The discussion was about the original mod release, and whether that constituted a fan game.

If it is made by a player, based on either the engine in the game used, or the content in general with modifications, THEN IT IS A MOD!!!!!!!!!!!!!!!!!!!

I was there more or less when the project started and it was questionable early on if it was ever going to see the light of day. The person who started the project had tried unsuccessfully with other properties.

This time he was able to secure permission from both George Brussard and Gearbox to finish it up and make it freely available.

You've always been able to make games with permission. Fan games aren't special in that respect.

Well, I guess we just fundamentally disagree on the semantics here. To me (and I suspect, to most people) a mod (in gaming terms) is something pretty specific - that is, something created that is not standalone and requires the original release to run. Again, I doubt anyone would really call Han Solo Adventures a 'mod'.

Dear god please read my post above. It uses the AGS engine but is a stand alone game it is not a mod and cannot be a mod if you don't have to load an original game first.

By your theory there are no games in the world only mods.

Because there's no real black and white "yes" or "no" answer.

If they have permission from the Copyright holder to use the property yes they are legal. If they do not no they are not as they are a copyright infringement and cannot be released in anyform.

Most fan games fall into the second category but are generally ignored (unless a new game is in development) and seen as free marketing for the original and/or guaging interest in a rerelease/sequel

::edit to add:: you can however take the premise of a game and reuse it as long as you don't copy anything covered by copyright (in many cases the names and locations etc) For example XCOM and UFO:AFTER(whatever) have a similar premise etc but UFO is not illegal as it does not reuse elements that are copyright to the XCOM series.

Apple are trying to change this in a way with their "look and feel" lawsuits technically as long as they are not identical they don't break any laws if they win it sets an unsettling precedent.. "Halo if an FPS and therefore has the same look and feel as our game DOOM and is therefore an illegal copy!!!!!!111one"

Apple's been at that since the 80s when they tried unsuccessfully to sue MS for stealing the look and feel that Apple themselves had stolen from Xerox. The ultimate resolution was that they lost because you can't do that.

However, you can potentially run afoul of a trademark though if you're not careful. Which is a much more realistic concern. Hence why so many clones end up only cloning gameplay and not anything that resembles the graphics.