Artificial intelligence is one of those interesting aspects of a video game that you don't tend to notice unless it isn't done well. Good A.I. is one of those things that blends into the experience, feeling natural enough that you never question it. The enemy soldier flanking you, the grenade just lobbed your way, you accept them because they are meant to simulate how such opponents would act in reality. Good A.I. copes with your good decisions and exploits your mistakes.
The first time I ever noticed a video game's artificial intelligence in a positive light, I was playing Fire Emblem for the Game Boy Advance. Its odd, I suppose, considering all the incredibly advanced games out there that it would be the game to stick with me in regards to that, but for all the limitations of its technology, Fire Emblem is a challenging game that constantly keeps you on your toes. The enemy is always quick to push and overwhelm you, exploiting all of your mistakes. Leave a character by themselves and you'll shortly find them surrounded. Expose a healer and every unit in range will target them. The A.I. does precisely what it's supposed to do, reacts effectively to the decisions of the player.
Unfortunately for ever example of good A.I., there are countless examples of bad A.I. in gaming. Playing the single player campaign of Battlefield: Bad Company, I was taken aback by just how poor the enemy A.I. was. They acted as little more than human gun turrets, rarely moving to avoid my shots, simply unloading round after round until I killed them. The only reason the game was difficult at all was the fact that the developers saw fit to endow the computer controlled soldiers with superhuman accuracy and the uncanny ability to know you're there before you had done anything to give yourself away.
Neglecting A.I., and in effect the single player modes that often rely on them, seems to be an evolving trend in gaming. In some genres like shooters and real time strategy for instance, no matter how realistic a developer can design an opponent to be, it's never a substitute for the real thing. Popping in classics like Goldeneye 007 today, modern gamers might be shocked to find how poorly the A.I. has aged, but add in a couple of controllers and a few friends and you're still probably going to have yourself some fun. Fighting live players is generally always going to beat taking on a computer. A computer controlled player can only do so much. They can only react in so many ways. People on the other hand are unpredictable.
With online connections practically a given part of life in America and many other gaming countries, the prominence of the multiplayer experience has grown immensely in a number of different genres and with it, its arguable the importance of A.I. has fallen off. Looking at recent releases in the shooter category for instance, one can see plenty of examples of the single player experience being increasingly neglected in favor of multiplayer. Call of Duty 4, in example, has earned mounds of praise for its addictive and challenging multiplayer. It won countless awards, topping a number of reviewer's lists for that year, and yet you'd be hard-pressed to find a single review of the game that didn't note how markedly short its story mode was. The multiplayer mode was clearly meant to be the main draw of the game.
Similarly, the aforementioned Battlefield: Bad Company featured one of the best multiplayer experiences in recent memory, but the single player mode seemed tacked on. Its problems extended far beyond its lackluster A.I. It just felt like playing a less fun version of the multiplayer mode modified to fit a storyline. It was as if the developers put it there almost out of adherence to an unspoken tradition, but didn't feel like putting in the effort to make it any good.
In some ways they can't be blamed. One of my favorite PS3 games is Resistance: Fall of Man, but I haven't touched the single player mode since I beat it the first time. The Darkness, for all its emotional whallop and advanced storytelling doesn't have much replay value to it, mostly thanks to its uninspired multiplayer. Its been pretty much proven that a game's value rises exponentially when good multiplayer is included. Some developers have taken this so close to heart, they have begun ditching single player modes altogether. Warhawk was launched as multiplayer only and has remained so, not without fiscal success either.
Evidence of this is readily available in more than just shooters. Real time strategy games have long had a strong element of human competition. One of the reasons that Starcraft achieved the rampant popularity it did was the fact that in addition to an incredible single player mode, it sported an addictive, and at the time, innovative multiplayer mode. Computer opponents were likely to stick with a few basic, preprogrammed strategies. A human player on the other hand was far less predictable and required you to play with an intelligence normally uncalled for.
This is not to say A.I. is completely pointless. There are just some genres where multiplayer isn't all that fun. Turn based strategy games for instance tend not to work as well with more than one person. Part of the appeal of that genre is being able to take one's time plotting out each move, weighing the pros and cons of everything you do. Against a computer player this isn't so bad because while you might take awhile to do something, the A.I. can more often than not react more quickly. Pairing human players however is often a recipe for slow, tedious gameplahy. Most players would rather not have to sit and wait for their opponent to think through their strategies.The development of better A.I. is a necessity to these kinds of games.
Furthermore, while multiplayer is assuredly more important than it was even just ten years ago, you'd have little luck finding anyone willing to spell off all single player experiences as pointless. The Darkness as pointed out earlier, might have been mediocre in some aspects of its design, but it still featured a story that was well worth the price of admission. Bioshock was void of multiplayer, but was centered on a plot that some gamers have proclaimed as downright philosophical.
For all that multiplayer can offer, single player campaigns still dominate certain facets of the video game experience. Few would argue that multiplayer is more adept at telling stories than single player is. There are always going to be gamers who value a good plot just as much as the they enjoy the thrills of a fragfest. For that reason alone forwarding the quality of artificial intelligence is a necessity.