Ideally, we'd be able to compare the sales of games pre- and post-ban and see how the regulation impacted them ... after accounting for all the other factors that might have also influenced sales at that time. The data we have don't really let us do that, though, so this is a slightly less scientific attempt to answer the same question, using some of the most controversial games of the past few years.
Let's start with an unusual case: Night Trap was released in 1992 for the Sega CD system; it followed five girls in a house with a mysterious past and made use of live-action video that featured, among other things, a girl in a nightgown. Despite a lack of actual nudity or real significant violence, it sparked a firestorm upon its release. You might expect a game rated "Mature" and released for an unpopular system to have some sales difficulties, and you would be correct – initial sales weren't particularly strong. However, the controversy over its objectionable content led to a boom in sales, and eventually to the porting of Night Trap to the PC and 3DO.
"MK was undeniably popular even before it attracted attention; some even blamed developers for including its over-the-top violence in order to interest gamers in the first place."
The next big controversy was probably Doom – no need to dwell on it, but needless to say, Doom was a success with somewhere near 2M copies sold and no doubt plenty more since that time. Yet did the controversy help it? It was already hotly anticipated and probably would have done quite well regardless. In fact, Doom is more of a shorthand for modern controversy than it was at the time. Its quality showed even before its release.
Finally, no discussion of this topic is complete without mentioning Rockstar – in particular, Manhunt and GTA. With respect to the former, the game got a mediocre reception from gamers (roughly 7s from critics) and has sold a little under 2M copies, according to Wikipedia. GTA has received pretty strong word of mouth, of course, and has sold well into the millions. Again, did the controversy help? It's hard to say, but it definitely doesn't appear to have hurt.
In the end, there seem to be basically two types of controversial games. Good games don't get hurt by the controversy, but they don't really get helped all that much by it either – they're already well-publicized and would probably sell just fine regardless of what the non-gaming public thinks of them. Those that aren't as strong, however, probably get a boost, and perhaps a significant one, because the negative publicity is really just a free marketing campaign. This suggests to opponents of controversial games that their best strategy is to simply keep quiet – even in countries where the games are entirely banned, people are still going to import (or worse, pirate) them.
As co-editors of A Link To The Future, Geoff and Jeff like to discuss, among many other topics, the business aspects of gaming. Game companies often make decisions that on their face appear baffling, or even infuriating, to many gamers. Yet when you think hard about them from the company's perspective, many other decisions are eminently sensible, or at least appeared to be so based on the conditions at the time those choices were made. Our goal with this column is to start a conversation about just those topics. While neither Geoff nor Jeff are employed in the game industry, they do have professional backgrounds that are relevant to the discussion. More to the point, they don't claim to have all the answers -- but this is a conversation worth having. You can reach them at