FWIW, we've been talking about them a lot here: http://www.chud.com/community/t/159637/wtf-is-the-latest-gaming-outrage-about
Microtransactions are just what they sound like. Games charging smaller prices for exclusive items to be used in the game. Sometimes these items are purely cosmetic, like character or weapon skins. Sometimes they're weapons or abilities that have an actual, tangible effect on the game.
Originally, these were devised as a way for ostensibly Free-To-Play games, which don't charge you anything to actually play, to generate some kind of income. League of Legends as an example, a rather popular game with millions of players worldwide, allows you to purchase different characters to use in the game in such a way. But you are given a starting character to use so you can play the game without paying a cent. This has generally been accepted as not too bad. The game is free and you can't expect the devs not to eat or do server upkeep with no income. Mobile Games like Candy Crush or Clash of Clans have been very guilty of milking these types of systems for all they can, and there have been stories of people literally spending thousands and thousands of dollars on these cheap but addictive games.
Recently however, and this is where the controversy is coming from, Full Price games by AAA Studios have been wanting a slice of that pie. So they've been inserting these Microtransactions more and more into games that just a few years ago didn't have to deal with this bullshit. The one that kind of started this whole problem in earnest was Blizzard's Overwatch. The game, $60 on Consoles or $40 on PC, had what are commonly referred to as Loot Boxes. Loot Boxes are essentially Lucky Packets filled with random cosmetic things like skins, voice lines or emotes of differing rarity to be used in the game. What you got all depended on the luck of the draw. Now, you can earn these Loot Boxes by just playing the game and earning levels or doing challenges. OR, you can buy collections of them and hope that you get that one skin you really want. They also frequently do Seasonal or Event skins 'n stuff only available at certain periods, like the Halloween Event currently going on, to tempt you to buy those Loot Boxes. Since the items in Overwatch are PURELY cosmetic changes and have no bearing on the actual gameplay, people generally accepted this. Although there were and are quite a few voices critical of the system.
The BIG problem though...has been that NOW Full Price $60 games are putting said items that have an ACTUAL effect on the game into these Microtransaction Loot Boxes. Battlefront 2, the new Star Wars Multiplayer game and Middle-Earth: Shadow of War are the two big, recent guilty parties. The Loot Boxes in Battlefront 2 especially, contain some pretty powerful items. So, in theory, someone who spends an extra $100 on these Loot Boxes and gets these powerful items, will have a noticeable advantage over other players who do not while playing. Essentially making the games Pay-to-Win and not very fair or enjoyable for someone who DOESN'T want to spend hundreds of bucks just to play a game they enjoy and not get stomped while doing so. Middle Earth: Shadow of War actually blocks players from getting the game's true ending by putting it behind a Loot Box paywall.
As you can guess, I and many others are not happy with these recent trends. It's blatantly predatory of these corporations trying to bleed us for every cent they can get. Hardly surprising and we should have seen the warning signs, but it's here now. And I fear it is here to stay cause they wouldn't be using these systems if they weren't crazy effective at making money. FWIW, I do not support them at ALL and encourage everyone else not to do so as well. Might be an impotent gesture, but I have my standards.