Open Source Multiplayer Source Ports and Cheating

Many of us know the story (though I personally haven't witnessed it): ZDaemon was open source, but due to the cheaters the source was closed. Would a popular open source multiplayer source port always be vulnerable to cheaters - is Odamex only cheater-free because people don't play it as much as Skulltag or ZDaemon? Or is it possible to make a good open source multiplayer source port (based on GZDoom or Vavoom for instance) similar to Skulltag which is cheater-free?

Keeping the source secret does not stop people from being able to develop cheats, but it does make it slightly more difficult. In the end, popularity determines how big a target you are, and keeping the source secret makes no difference.

Read The case of the Quake cheats.

"Open source keeps designers honest. By depriving them of the crutch of obscurity, it forces them towards using methods that are provably secure not only against known attacks but against all possible attacks by an intruder with full knowledge of the system and its source code. This is real security, the kind cryptographers and other professional paranoids respect."

As the Quake article points out, aimbots and wallhacks can't be fully defeated by security through design, which makes a layer of security through obscurity a benefit in this case. But, as the article also points out, these cheat programs can still be built without access to the source code, so releasing the source for ZDaemon or Skulltag wouldn't introduce fundamentally new weaknesses to those programs; those weaknesses were already there.

However, it's been a concern of mine that there are malcontents who aren't skilled or determined enough to design cheats for Skulltag or ZDaemon at the moment, but who are skilled enough to design cheats with the aid of those ports' source code. Fortunately, in the small everybody-knows-everybody communities that these games have (for the most part) such individuals could be discovered and dealt with individually, or perhaps they don't even exist.

So, an open-source Doom multiplayer port with a larger player community would probably work. However, ZDaemon and Skulltag remain closed-source because their developers and most of their players feel that keeping the source closed is working already, so, to them, the gains from opening the source code aren't worth the gamble.

Creaphis said:

Stuff

Trying to defend these cowards again? ;)

Graf Zahl said:

Trying to defend these cowards again? ;)

Well, I still believe that "open source is the perfect solution to all problems and has absolutely no drawbacks whatsoever" isn't the most neutral or correct position. But, I don't want to start shit - I'm not proud of that other thread.

Creaphis said:

Well, I still believe that "open source is the perfect solution to all problems and has absolutely no drawbacks whatsoever" isn't the most neutral or correct position.

Don't forget the moral implications. These ports take from developers who release their source after all.

I consider that as a strong argument in favour of a Skulltag source release (to return to that dreadful argument). Note that my first post in this thread doesn't say, "The developers of Skulltag should keep the source closed," it merely states why they have chosen that tack. I suppose that they have a more pragmatic view of the morals involved - what works is what is right. I admit that my moral code is fairly pragmatic as well, but my system of ethics isn't the topic of interest here.

The article was a fun read.

I have an idea about how to prevent aimbotting: make all weapons projectile. It's a lot harder to hit your opponent with an aimbot if it takes time for the shot to him them than if it doesn't. You have to use various interpolation techniques in your aimbot, which will never be as accurate as a skilled player in the forseeable future (and are significantly harder to implement than a pure aimbot). Then again it won't be "DOOM" anymore.. at least it would sort of fit into a "Heretic" world, with all the bolts of magical energy flying around.

It seems performance is even more of an issue in the classic DOOM community than most more popular FPSes. If you have broadband, you can probably easily find a server with <100 ping and even <50 isn't too unlikely: due to the amount of servers available, there will likely be one that is quite nearby. In Counter Strike: Source, I often play on servers with about 20 ping. On the other hand, I am not sure about ZDaemon, but pings of about 200 are standard in Skulltag due to there not being that many servers or players compared to games like Unreal Tournament 2004 or Counter Strike, thus US people playing on EU servers and vice versa. Yesterday, I was playing on a US server with some people from Australia, and they consistently had over 300 ping, and thought it was normal. This makes a client with limited information even more difficult to implement.

There is an old version of the Skulltag source freely available also, by the way. I wonder what implications that has. Maybe the design is more secure than ZDaemon's to being with, thus the lack of aim bots or wall hacks.

Some very powerful aimbots out there make trajectory calculations that take into account their opponents' direction and speed, and therefore are immensely powerful with projectile weapons. Good try though; at least you're thinking.

Creaphis said:

Some very powerful aimbots out there make trajectory calculations that take into account their opponents' direction and speed, and therefore are immensely powerful with projectile weapons. Good try though; at least you're thinking.

Doesn't this only work if they're not changing directions? Any reasonably skilled player can lead shots too...

And if someone consistently tries to shoot ahead of you then it's not that hard to dodge their shots by simply changing directions...

Even ZDoom has an action special that does this, and you can make monsters do this if you want...

Spleen said:

Doesn't this only work if they're not changing directions? Any reasonably skilled player can lead shots too...

And if someone consistently tries to shoot ahead of you then it's not that hard to dodge their shots by simply changing directions...

Combine this bot with a wallhack, and every other player will run smack into a rocket every time he passes a corner.

Creaphis said:

Combine this bot with a wallhack, and every other player will run smack into a rocket every time he passes a corner.

Ouch, interesting idea. However, what if you only have an aimbot and no wall hacks. :)

Graf Zahl said:

Don't forget the moral implications. These ports take from developers who release their source after all.

http://everything2.com/index.pl?node=BSD%20Code%20in%20Windows

Spleen said:

Ouch, interesting idea. However, what if you only have an aimbot and no wall hacks. :)

Well then the bot-user still has some advantage over legitimate players, even if players can evade the bot's projectiles from time to time. I'm just saying that, as a way to cripple bots, making all weapons projectile weapons is not effective.

Catoptromancy said:

http://everything2.com/index.pl?node=BSD%20Code%20in%20Windows

Ha. See, you don't need people like me to embrace the Free Software ideology. With enemies as clumsy and hypocritical as Microsoft, who needs friends?

Spleen said:

I have an idea about how to prevent aimbotting: make all weapons projectile.

Deathmatch with imp fireballs? :) Now that's gonna be slow.

edit: To add something to the discussion, some people will always cheat. Play only with people you know if cheating is an issue.

Jodwin said:

Deathmatch with imp fireballs? :) Now that's gonna be slow.

The projectiles don't have to be *that* slow. Think rockets and plasma :)

It's actually very fun. You should try Heretic Element Storm competitive game mode edition.