How did you come to the conclusion that I think multi-player is inherently bad?

And I am programming a multiplayer game and the architecture for it uses both a "master server" (or lobby) and per-player keys but because they won't be for enforcing DRM, I can architect them to provide a better experience instead of interfering with the players.

As for the multiplayer key, how do you figure the honest user is inconvenienced less than a pirate?

User finds their key is currently in use:
Pirate: Generates a new key, goes back to playing in <10 minutes
Customer: Contacts the key-giver (if they still exist) and requests a new key. Has to provide money/proof of purchase to receive new key. Process takes >10 minutes.

EDIT:
And here is why people focus on the negative side of it:
When it works, it's neutral.
When it breaks, you lose.

I quote "adds unnecessary dependencies and failure points to a system which inevitably inconveniences ... the honest customers"
Master servers do that, when they go down. Take a look at what happened to XMP (Unreal 2's multiplayer).
Maybe the master server can be worked around, but there aren't many good options. Same with serial-key/unique-ID based bans for servers. There are alternatives, but it is hard to really think of a good one that doesn't force the admins to repeatedly ban someone who just flicks the power on his or her modem (without banning entire subnets).

Are you going to let anyone play your multiplayer game, regardless of if they have a legal key?
Congratulations, you have DRM. One of the weaker models, but DRM. :p
Have you ever used a keygen (for games)? Most of them (actually, I think almost all of them) don't "generate" a new key. They just keep going to a pool of keys. Otherwise, everyone would have a free copy of Half-Life and Counterstrike.

Where do these keys come from? Stolen from boxes (at which point, the user just yells at the store for selling an opened copy), stolen from users (because said user wanted a hack/crack and is too stupid to virus scan), or magically plucked from the aether (at which point, we get to statistical improbabilities).

That still doesn't say I think multi-player is inherently bad.
Requiring an internet connection to play a game across the internet == necessary.
Requiring an internet connection to play a game across the LAN == not necessary.
Requiring an internet connection to play a game on the local machine (single-player) == WTF :P

Yes, because all the "keys" will be legal. You'll be able to generate a new key from within the game because it isn't being used to enforce DRM. It's purpose will be so the server can tell if you are the same person who was previously connected (but differentiate between people with the same IPs).
If the installer doesn't check the key remotely, it has to use an algorithm to check if the key was valid. After discovering the algorithm, it would be easy to generate new keys which "pass" this check without a pool. If the key is checked remotely though, whole different ball game (as the key would need to be activated).

And again, the paying customer can get burned. A new virus going around which harvests keys for a game, which get added to a keygen, which then get black-listed from the server. Honest user has to get a brand new key while a pirate just uses one that isn't blacklisted.

Yes, but I was referring to the Master Server and for the ability for it to be immediately taken away with no warning. I actually fully agree with you on the three points you just mentioned here.

Ah, so a freeware game. And that does nothing to solve the hacker/troll/griefer problem. But stat tracking is nice :p

How likely is it for a "generic" virus to harvest keys for specific games? Not likely. Because even with everyone and their mother owning a copy of Modern Warfare 2 (if sales are to be believed :p), it still wouldn't be worth the time (or "cost") to make a generic virus that infects everyone in the hopes of having a key on that computer.
So we still get the targeted viruses. The false hacks.

And even local key-checking is pretty hard to reverse engineer, if it is by any dev/publisher worth their salt. Like I said, Half-Life 1 didn't require an internet connection at all, and all the "offline" keys for that game can be used with Steam to get the entire GldSrc catalog from Steam. Yet all the keygens (as of a year or two ago) still rely upon a simple pool of keys. Why? Because reverse engineering is a bitch :p

So the honest user is still safe, as long as they avoid buying used/opened copies. And if there IS a magic virus that infects a large group of people (because any non-targeted virus would have to infect a large population to be guaranteed to get even a few keys), contact the publisher. And if the publisher is out of business, the Master Server is gone too, so you couldn't play MP anyway.

I'm amused how you came to the conclusion that "DRM free == freeware" :)
Perhaps I am just sane enough to realise that my paying customers are important and I've not yet thought of a system to prevent illegal copies without severely risking causing grief to paying customers... though your conclusion is correct, it will be an freeware game (GPL, to be more precise) :)

Unless they paid another company to run their master server in which case the server is still up, but no new keys. And a generic virus to harvest keys for one game might be unlikely, but a virus which harvests keys for several games or one that is part of a botnet (thus, can get "custom" payloads) is much more likely and would be more effective.

Now I just have to hope I've not given anyone ideas :P

To make a profit, you need some way to restrict the use of something (unless we are counting on donations, which is still freeware, for all intents and purposes). Some way to manage people's rights to activate something :p

But nah, seriously. If you are giving an infinite number of keys to people, then it is highly unlikely you intend to turn a profit.

And you are right, it is all a balancing act. Provide enough DRM/"Magic thing that isn't DRM but serves the same purpose". I just happen to feel that a SIMPLE "unique ID per user to ban people from servers" model is pretty lenient and has no real drawbacks.

If they have enough money to pay for the server, they can pay for the generic office that handles requests (since that is publisher-based).

And the effort required to make a botnet to "customize" every virus is, again, well beyond the worth. MUCH better uses of time and money (like credit card info, which lets them buy their own copies :p).

Haha, very true :)

However, I think the groups of people that break DRM and make these keygens and stuff are more in it for the reputation than the monetary gains. Whether there is a large enough cross-over between virus/botnet creators and these groups is another matter though!

The following games are missing on the list:

Spellforce Platinum
Ground Control 2
Painkiller Black Edition