Mass Effect 3 multiplayer is essentially a “free-to-play” game that is included alongside the main campaign. You pick a character class, select your weapons and attachments, and play 10 rounds against increasingly difficult waves of enemies. Depending on how far you were able to get, and what difficulty you chose, you will get a number of credits to use in the game’s store, where you can randomly unlock new characters, weapons, attachments, and assorted gear upgrades.
The harder you make the game, the more credits you can earn for playing. The more credits you earn, the faster you can afford the most expensive upgrade packages, and the better your chances of unlocking new characters and equipment. So Electronic Arts was perhaps justifiably a little concerned when players uncovered an exploit on the map Firebase White that allowed even mediocre players to succeed on the hardest difficulty, and quickly earn a massive amount of credits with a very low chance of failure.
This was even more of a concern for EA due to the profit that they earned from the game. For people who were impatient, rather than repeatedly attempting to earn credits by playing the game, they could instead choose to buy credits. People could spend real money, to get virtual money, to spend on random upgrade packages, that in no way guaranteed the player that they would unlock anything they were hoping for.
This business model proved to be so successful for EA that several free DLC packs were made available. These included new maps, enemies, characters, weapons, attachments, and other assorted gear and upgrades. The maps and new enemy classifications were all instantly available, while everything else had to be unlocked at random.
So in order to deal with the map geometry exploit on Firebase White, one of the updates radically changed the map’s layout, and eliminated the highly defendable position on the far side of the map. To sugarcoat the change, the game’s developers kindly included optional danger zones for all of the original maps, but Firebase White received by far the largest change to any map’s basic geometry.
Although you could make the argument that nobody forced players to download the updated maps, it would be impossible to ever use the new classes and weapons without also downloading the massive change to Firebase White. And while Mass Effect 3 would allow you to continue playing the game without downloading the most recent update, that situation was never true for what I feel–as far as video games are concerned–just might be the most egregious example of altering the deal I’ve ever seen.