In short: you cannot simply just keep “adding stuff” to a game and have it retain its solid fidelity. There is a point with every game where adding one more monster, one more gun, one more playable class is too much. This may not entirely break the game, but it does degrade it. The quality and significance of each decision is slightly diminished, the identity of elements blurred.

Adding stuff to a game has multiple reasons, the majority of reasons have nothing to do with game design, more likely with business.

You can't compare games like chess with BF2/TF2, because chess is a game concept, a rule set, and not a product. To some degree you need to compare chess to a FPS or a RTS or a RPG and then you will see, that a FPS/RTS/RPG has not been greatly expanded since the first nethack,doom or warcraft game. Considering that games like chess evolved over 100 of years, a FPS/RTS/RPG game will be almost the same in 200 years, just the appearance changed, like a chess board from an other manufactory.

Take a look at half-life. This game was mostly a single-player game, but the real success was its multiplayer part due to great modding support. This game was one of the first one which demonstrated the power of solid game community. First, a multiplayer game is much more likely to generate a online community, secondly you need to feed your community to keep it at it. You know that gamers want to play, and that they will leave your game (more importantly your community) to join something else once the get bored. This is the main reason, publisher provided ongoing content: to keep the people in their game until they release the according sequel

It is just standard business, like a payback card from your discounter. They don't want to directly influence the amount of products you consume (that is markting), they want to influence from where you get your products(when you buy it, buy it from us).

It isn't a secred, the industry want your money, not your happieness. So, when you want to make games which makes people happy, don't expect to get rich (play lottory, it is more likely to have success with it).

I love forum PR.

Another point about DLC is especially true with retailers like GameStop. It is irritating how fans become fragmented depending on what platform you have, where you bought the game, and when. I don't see how this improves the game at all, but I do see how it encourages sales at one establishment at one time as opposed to any other. Maybe it's just "one of those things", but just why?

Ashaman73 is correct in that most of the reasons for this are to do with the business side of game design. Not just with the designer/publisher but also the retailers and hardware manufactures. At points it can improve the game (e.g. not making console players face off against PC players in an FPS) and there are companies trying to work around it to an extent (the Witcher 2 Enhanced Edition which was just announced is a nice example of a secondary release that still rewards original purchasers).

The issue of platform segregation will evaporate as cheaper more powerful and portable hardware appears to the point you will only ever need one device that can do everything. Sadly some of the other issues (like special deals at certain retailers) are largely here to stay (unless only one company comes to dominate completely which would result in a much worse situation).

Ashaman73 is correct in that most of the reasons for this are to do with the business side of game design. Not just with the designer/publisher but also the retailers and hardware manufactures. At points it can improve the game (e.g. not making console players face off against PC players in an FPS) and there are companies trying to work around it to an extent (the Witcher 2 Enhanced Edition which was just announced is a nice example of a secondary release that still rewards original purchasers).

The issue of platform segregation will evaporate as cheaper more powerful and portable hardware appears to the point you will only ever need one device that can do everything. Sadly some of the other issues (like special deals at certain retailers) are largely here to stay (unless only one company comes to dominate completely which would result in a much worse situation).

I understand that it's games as a business. The butcher, baker, and candlestick maker all want their share. For just that reason, one cheap platform to rule them all won't happen, evenif it would be nice. Instead, people pick favorites, they divide themselves into "camps", and the kings of the marketplace vie with each other to conquer all under heaven intact, or at least a good chunk of it while they can. Yada yada yada.

Anyway. I haven't actually commented on the original premise of this thread. That's because I really don't see one true way here, or how either method being discussed is orthogonal to the other. But let's discuss one of my favorite video game heroes, shall we?

Megaman has had dozens of sequels and spin-offs. There were 6 Megaman games on NES alone, and that was over a span of about 4 years. They all looked much the same, but each added little things. For instance, Megaman 2 was more playable than the original, you could slide in Megaman 3, and in one of the others you could charge your buster for the first time. However, it definitely got repetitive and "degraded" after Megaman 3. (Megaman 2 is still one of my favorite games ever. )

Now, of course, you had all these sequels for the simple fact that you couldn't just connect your NES to the Internet and download the latest episode of Megaman off Steam or what-not. So this could be viewed really either way: Was Capcom making expansions and incremental changes or completely new sequels with each game? They sure looked the same. They sure scrolled and tiled and animated the same. They sure sounded the same, except maybe the music. And considering that they were probably written in 6502 assembly, it's understandable if the code didn't change all that much or if only small changes to the core design were ever made. It could thus be said that the first true "sequel" to Megaman, as opposed to an expansion, may have actually been Megaman X, and then Megaman 7 when that was released.

The fact that the NES Megaman series went on for 3 more "expansions" after Megaman 3, and that I really can't find anything memorable in them except charging a gun ("Whoa, we got a badass over here!") means that the game did start to degrade with each "expansion", as the OP said. It would've been perfectly fine to move onto other things. Ah, but here we come full circle. Because why did Capcom keep expanding this game? Business.

Yes, business can be responsible for some really silly things. It itself is a strange game. (One could argue that) the only winning move is not to play. How about a nice game of chess?

Old rule -- if your are being repetative/redudant dont add it ....