Gameplay Complexity and Opponents

Yesterday in my praise of the fantasy MMORPG as the ultimate genre, I touched on the notion that a game that involves human-like opponents has a lot of natural potential for rich gameplay. Today I want to expand on that a bit.

Game genres range from racing to shooters to RPGs to slot-machines to sims to platformers and on. Multiplayer games obviously pit you against other humans. Some of them have single-player variants, where the part of the enemy is played by AI that tries to act as close to human; ie, the opponents have the same range of actions and strategies as humans do. Others pit you against a puzzle, or simplified enemies with very constrained actions.

Puzzles - No Opponent

I'll start with the last. Puzzle games like Tetris don't have "opponents". It's just you against the puzzle. Simulations, including games like SimCity and Roller Coaster Tycoon, pit you against a complex puzzle. Simple puzzle games have simple mechanics; the complexity of the game is how the rules fit together. Some such games are like skill games - gameplay at the higher levels of Tetris require the player to have internalized the gameplay rules effectively to the point that it's like a sport, and where reflexes and the ability to think a few moves ahead are important.

Skill games are rarely complex. Coding their game rules is simple. Design can be difficult, however; the process of coming up with rules that are amenable to skill is tricky. Back during the golden decade of the FPS (the 1990s), many game companies tried to make competition-worthy FPS games, but most fared poorly. For a single-player game, something that's going to provide 15-40 hours of gameplay, the game mechanics don't need to be very rich. Elements that would lend themselves to longevity as a skill-based competition are hard to design in, and the economics of the game industry often mean that the people that would have experience with competition-style gameplay aren't the ones that are chosen to lead game design. It's one thing to say "we want a lively online community" and another to actually spend money and effort finding a designer that can do that well. There's a rich discussion there but I'll skip it for now.

Because my point is: the complexity of these games is usually the intricate ways in which a small set of game rules combine.

Could you turn a sim into something players would spend a thousand hours playing? How long could you play Roller Coaster Tycoon before you exhausted the whole game? Do you think you could convince a million players to each put a thousand hours into it? These games (on the PC) are lucky to sell a million copies. Most of those players might put less than a dozen hours in.

What would it take to make a sim or puzzle game that players spend that much time on? It feels silly to even think it's possible, since one hundred hours is a stretch for these games. Maybe there's some diehard fanatics that put that much time in (the Transport Tycoon community is one such example), but that's a tiny community. That's maybe a thousand players - not a million. I'd like to explore this idea further... and indeed I do in this followup post on the thousand-hour sim.

Platformers - Fake Opponents

Platformers have opponents, but they aren't anything like human players. Enemies such as the goombas in Mario follow very rigid rules. They don't even try to behave like human players. That's not the point; these are effectively puzzle games where part of the puzzle is an AI-controlled "humanoid" character with simplistic, predictable rules.

Usually there's not a lot of richness to these games. They're exploration and achievement games, with a little bit of skill thrown in. Gameplay is fun, but that's driven in part by the environments, not the opponents. The human (or sentient) appearance of the opponents just fills out the game world; makes it seem like a real place and less like an abstraction.

Recent Mario games (such as Mario Galaxy) do wind up being somewhat rich, but not too much. Most of the richness is in carefully timed execution of special moves. In other words, they are skill games. Puzzles are straightforward, the interactions of gameplay elements are rare, and the focus of the game is more on exploration than anything else.


Head-to-Head Action and Strategy Games

Whereas there's no real "opponent" in puzzle or sim games, and simplified opponents in platformers, other action games have real humans as the opponent. RTS games like Starcraft and FPS games like Counter-Strike fit this model. Even when you're playing against the AI, that AI is trying to act as human as possible.

Both you and your opponent have the same range of abilities. Chess is a simplified version of this model, where both players have exactly the same units at their disposal. FPS games are similar; often skill games (see above), but the richness in the game comes from the fact that the opponent is truly human and so not only has a huge bag of tricks but can also learn new tricks as time goes on.

RTS games rely heavily on the humanness of your opponent, but they often twist gameplay by allowing players to choose different "races." Starcraft is the standout in this model. Most Starcraft games are played by players of different races; Terran, Zerg, or Protoss. They are all basically doing the same thing - placing buildings, recruiting soldiers and ships, and sending them off to attack. Yet the units that they have are different, and their overall approach to winning is different as well.

The richness in FPS games comes primarily from the human opponent. The fine balance of rules can make the game more or less balanced; more or less random. Yet it's the humans that make them great.

RTS games, however, add much more. There's a lot more strategy to RTS games. Choices made early - not just single actions, but choices to develop in one way or another - define the game. Do you try to tech up? Rush? Expand early? Press to aerial units? Fake one build but go another way? Where FPS games often have rich tactical fights, RTS games also have strategic fights.

RPGs

RPGs are a bit like RTS games, in that you are facing human-like opponents with skills and actions similar to your own, but with a different strategic twist. In Starcraft you have Protoss vs Zerg, in WoW you'll have a Rogue against a Warlock.

Humans provide the richest opponents. Some are better than others; in RPGs, you might face someone that doesn't know their class very well at all. But most of those that engage in PvP know what they're doing. Competition ladders help great players find similar opponents, while allowing the crappy players a chance to win every know and again against other new (or... well, crappy) players.

RPGs add more to the single-player experience, however, by having a much longer stretch of new abilities. In an RTS, you'll become familiar with all of the units and buildings at your disposal over the 30 hours or so in the single-player campaign. In an MMORPG, there can be hundreds of hours of advancement before you've gotten to the top of the ability tree, learning new spells or abilities every few levels.

Instead of giving you a small set of tools with rich interactions, like chess, RPGs have a much larger set of tools, each with its own special purpose. The trick isn't to learn how the abilities interact, but usually which ability to use when; how to fight against certain types of opponents. The huge array of possible opponents is what makes the RPG rich.

Human-like Opponents with Different Tactical and Strategic Choices

My goal here was to explore the game design choices that produce a game that players could enjoy for hundreds of hours. Leaving aside the diehard fanatics that might stick to their favorite title long past when the majority of the market has gotten bored, we're left with three major avenues.

The first approach is to build a game that requires player skill, whether solo or competitive. Players spend their time getting better at those skills. Games like Counter-Strike and Tetris are the best examples, but even then they point out the weakness: although both have audiences larger than (say) Transport Tycoon, these are still relatively niche titles. Lots of people love them and (relatively) lots put in over a hundred hours playing the game, but there are bigger genres out there.

The second approach is to create simple mechanics with extremely complex interactions. Chess is the canonical example. Players have a chance to learn ever more complex interactions. Every time they play, they probably learn another new trick. The success of this genre depends on the size of the market, however. There can't be hundred of Chess-like games, because the complexity of interaction depends on the size of the market. Not everyone has the talent to be a grandmaster, and in order to even get grandmasters, you need enough people to push the curve that far.

The third approach is pitting player versus player. Whether you've got a skill-based game, one with simple rules but complex interactions, or complex rules, pitting humans against each other means that rich gameplay will evolve. You'll either need to do a whole lot of playtesting and balancing or be willing to tune the game after it ships, but with PvP, humans will figure out complex strategies.

Personally, I think the two richest game genres are the RTS and the RPG. The best, longest-lived games in both genres have PvP (sometimes simulated), complex gameplay interactions, and a measure of player skill. If you want to create a game that pulls in players for hundreds of paid hours, you'll need more than one of the approaches.