Game Design Sketchbook: Testing the Limits of Single-PlayerGame Design Sketchbook - RSS 2.0
Go is often cited as a touchstone for profoundly deep gameplay that emerges from a shockingly simple set of basic game mechanics. You can learn the rules in less than a minute, but you can spend the rest of your life plumbing the depths of this game. Go is a game that you can return to over and over. It will always have something new to show you. It will never grow old.
As simple as Go's design is, Go-deep gameplay for art games, or even modern videogames generally, seems to be a tough nut to crack. Infinite replayability? It's almost unheard of. After you've honed your thumbs until they're pumping like well-oiled machines (in Geometry Wars), found every last collectible (in Super Mario Galaxy), or learned how to out-smart the AI (in Starcraft), can you really come back to a game in the future and find further value in it?
Where are videogames going wrong, then? Industry-wide design wisdom tells us to give the player interesting choices, and we really try to make games that do this, but somehow we're failing. Can't we study board games such as Chess, Othello, and Checkers and learn from them? We can and we have. It seems that many of these board games create interesting choices out of several interlocking mechanics. So, we add some interlocking mechanics to our videogames, but we see very little added depth as a result. We add layer upon layer of mechanics, but nothing seems to profound-ify our gameplay - nothing that will keep the player thinking and learning forever.
What about Tetris? There's a videogame that you can come back to over and over. Optimal play is probably unattainable (the game is known to be NP-hard, and that's assuming that you can see the entire future piece queue), and the speed-up as the levels progress provides an endless physical and mental challenge. But gradual speed-up doesn't feel like the key to gameplay depth; it's a classic gimmick used in hundreds of arcade games to create eternal challenges. Learning how to play Centipede well, for example, is akin to learning how to juggle more and more balls.
Let's take the time factor out of Tetris - say that you get to think for as long as you want before placing each piece. Would it still be an interesting game without the reflex challenge? I think it would. The randomness of the piece queue, combined with the optimization problem, makes every new game a fresh mental challenge. What if we take out the randomization? Suppose every game of Tetris presented you with a series of pieces in exactly the same order? That would leave you with just a single instance of the optimization problem (how to best pack this particular series of objects into the well) to try over and over on subsequent games. I believe this change would sap the gameplay depth out of Tetris, changing it into a scored puzzle. After settling on the best way you can discover to pack that series of pieces into the well, you would quickly lose interest.
So is that the key? Randomization? But classic board games like Go don't involve any random elements. The card game Solitaire does, though: Each new game offers a new sequence of cards for a fresh mental challenge. People can play thousands of games of Solitaire without exhausting its depth.
Considering Solitaire finally leads us to answer our question about deep gameplay. Why does Solitaire need randomization while Go does not? What does Solitaire have in common with Tetris, Centepede, Braid, and almost all the other videogames mentioned so far?
These are all single-player games, while all the deep board games require multiple players. In fact, the vast majority of videogames are single-player games. Raph Koster has observed that the single-player tradition stemmed primarily from technological limitations; computers were not connected together in the early days, for example. Koster's focus was on the absence of human contact in single-player games, but the absence of deep game mechanics is just as interesting.