When people talk about game physics, they’re really talking about three different things.
1) the actual physics of a ball being affected by gravity, elasticity, and air drag.
2) collision detection; knowing when the ball touches the wall.
3) collision resolution; Handling the ball bouncing off the wall and not penetrating it.

I’m doing that right now in some procedural research I’m doing, and I’m pretty happy with my approach so far.

What I’m doing is…Making a collision box around everything I’m not supposed to penetrate, and excluding the player from that box. I detect that the player winds up in the box after applying all my forces, and if so, I move the player out towards the nearest face.

Now, there can be some problems with this method. First, the player can slip between two collision boxes that abut each other. The solution is simple; make them overlap a bit.

Another problem occurs if the player tries to move into the concave corner formed by two coll boxes. You don’t really want them to overlap in that case, since it causes a weird join the player can get hung up on. But if you don’t overlap them, the player can slip right thru between them. The answer is to put a third coll box (or just a coll face, facing the concavity) in the join. A coll column works well, too.

Still, this is a nice system, since you never have to worry about starting your move inside something (which can get you trapped inside a coll box, using other methods). You also don’t need to bother stepping out of the coll box plus a little bit, like I’ve had to do on other projects. Also, the system meshes perfectly with a Verlet physics system.

Nowadays, there are really good physics systems you can get for free. These systems start with their own assumptions, but they encompass all three of the things I mentioned at the top of this post. One day I’m gonna have to check them out.

Go away, Spambot!

Some stupid spambot is dumping weird and seemingly pointless spam in my comments, several times a day. I accept that my cleanup of it is just my penance for allowing anonymous posting here, but I’d be less weirded out if it were male enhancement spam, or pharmacy spam.

Instead it’s a series of 5 big, unusual words (like confiscatory, or byzantine), followed by 5 URLs (which are nonsense and don’t exist). Weird. If you have any idea what the point of this spam is, please enlighten me.

Austin Game Conference ’08

Less Is More. That was the main message I got from the AGC, which I attended last week. I saw plenty of interesting panels and lectures, caught up with lots of old friends, and grabbed a few t-shirts from the exhibitors’ hall.

I also learned that multi-player gaming is in a golden age, gold rush, experimental explosion. Everybody’s trying everything, and most of it’s working. From deep MMORPGs to facebook apps, the definition of a multiplayer game is being stretched past the breaking point.

Why do I say…Less Is More? ‘Cause I heard the message several times that (to reach a wider audience) developers should trade more dungeons and monsters for a more polished and effective UI and clearer instructions. I should just say "instructions", because the number one gripe people have with western MMOs is that they’re profoundly impenetrable. You have to read 5 websites and troll pages of forums before really understanding the mechanics of WoW.

So alternatives like Club Penguin, Habbo Hotel, and a new game called Wizard 101 stand up to give players a trouble-free play experience, and they’re very popular. Not just with kids, but with older women, too.

Just about every money model is working for someone, too. Subscription, item-supported, player tiers, ad-supported, someone is making money off it. Kids still have NO access to credit cards, but game cards are now ubiquitous (they weren’t anywhere two years ago).

I heard plenty of stories detailing how the game industry continues to make the same mistakes and fail for the same reasons as always. I also got more info about what it’s like to work for Disney. Two words: soul crushing.

And it was a successful show, in the sense that I came home inspired to make cool new games. Plus I didn’t bring home a cold. 🙂


The video game definition of an avatar is the representation of the player in the game space. Usually, that representation is a 3D humanoid which is directly controlled by the player’s input device. This term, "Avatar", really came into wide use because of MMORPGs, but the basic concept is as old as video games themselves.

However, there are plenty of games that have no 3rd or 1st person avatar, like turn-based games and RTS games. I argue (and many agree) that in that case, your avatar is usually the mouse cursor.

Which brings us to the reason for this post: What OTHER forms could an avatar take?Aside from a little guy, or the mouse, how is the player expressed in the game space?

Well, text adventures and early games didn’t have a mouse. For text adventures, it can be argued that there really isn’t MUCH of an avatar, but I think there’s enough. The games constantly talk about "You", and "you" can move from room to room. So I guess the avatar is still a little guy, just without the graphics or the extremely reactive controls. Graphical adventures, like Kings Quest and Monkey Island, bear that out.

There are certain sports "manager" games that are so full of statistics and buttons that it can be argued that the player doesn’t HAVE a representation within the game space. If all you are doing is calling plays from the sideline, are "you" on the playfield?

Speaking of sports games, normal action sports games typically let you (the player) jump from avatar to avatar, often very quickly, but you still only control one little guy at a time.

It’s possible that I’m looking at this from the wrong end. We have avatars so that we can VERB the game. In other words, we use our avatar (guy or mouse) to do the tasks that make fun. Perhaps I should be looking for verbs that cannot be accomplished by little guys or mouse pointers, then try to imagine what kind of avatar would be more appropriate for that verb.

As an aside, an avatar is NOT a protagonist!!! That’s movie/writing thinking, and pointless from a game design point of view (did I mention I dislike Hollywood?)

The six types of gameplay

For YEARS, I’ve had a taxonomy of games in my back pocket. It used to be 4 atomic types of gameplay, from which all games could be created:

Content Navigation
Resource Management
Tactical Wargaming

But years ago, my friend Mike Steele helped me identify two more types:


Let’s go into more detail…Content Navigation is the "game" part of a graphical adventure; not the content itself, but moving through the content. Choosing the correct dialog option, opening the door, and extending the bridge are all navigation of content.

Resource Management is the act of using 10 of something to get 100 of the same thing. If you use your sword to get 10 gold pieces, then spend that gold in the shop to buy a better sword that lets you go out and get 100 gold pieces, that’s Resource Management. It could be gold, credits, or quatloos, the denomination doesn’t matter. What matters is that you spend money to make money.

Tactical Wargaming is an expression of opposing forces over space and time. If you bash a monster, and he can bash you back, that’s Tactical Wargaming. Why tactical, why not strategic? Well, the larger scale of strategic wargaming is really a combination of Resource Management and Content Navigation. Only the actual battle is an atomic gameplay element.

Twitch is the so-called "real time" element. I describe it as a game which interprets no input as valid input. A fighting game has twitch, because if you put the controller down and walk away, the game will still kick your ass. When a game is NOT twitch, it will patiently wait for you to pick up the controller again. I feel it’s really important to note that twitch is a binary state. No matter what anyone says, no game can be "sorta real-time". Different parts of the same game can be twitch or not twitch, but one game mode cannot be both at the same time.

Creativity is the creative act within a game, and usually implies some kind of editor. In a race game, the editor that lets you paint and customize your car is Creativity gameplay. But is it even gameplay? Sure, in the critical sense that Creativity is a valid form of fun. Many, many people spend hours in front of an editor of some kind, simply because they are having fun building a 3D model or making a web comic or composing a song. When that fun is part of your game, that part is the atomic type called Creativity.

Multiplayer is the act of communicating with, and playing with, other human beings. Like Creativity, it’s clearly fun, and it doesn’t fit the other five types of gameplay. It is its own form of atomic gameplay.


Why did I write this now? Well, for one thing, it hasn’t been mentioned on this blog before.

But for another, I’m really feeling the constriction of this model. I’ve been hoping to find a seventh and eighth atomic gameplay element for years now, and hoping that it could lead to new gaming vistas. But no dice; today’s games can still easily be described as combinations of my six atomic types.

What Is "Fun" Anyway?

NGai Croal writes another thoughtful post that resonates with me.

I’m not saying I totally agree with it; in particular, I’m not sure that getting older is the proximate cause of our changing gaming tastes. I suspect that our increasing knowledge and understanding of games and game systems has more to do with it.http://www.edge-online….

Austin Game Developers Conference

I’ll be attending the Austin Game Developers Conference on Sept. 14-18 (Thanks, Linda!!!). It’s always fun, and I always rub shoulders and have meals with people I know, or people I SHOULD know. Austin is also my old home town, so there’s always good friends to hang out with and restaurants to revisit.
I’ve made MMO games before, and probably will again, but the show itself has a tremendous focus on MMO game development (though there are game audio and game writing "tracks"). I’m always happy to learn more about MMOs and how to make them. Last year, NCSoft gave a presentation on how they used data logging to make their Dungeon Runners game better. I learned a lot about the methodology you have to apply to get and interpret meaningful data.

To one degree or another, I always come away from the AGD Con filled with creative energy and new ideas. That’s not to say that the con necessarily provides new ideas; my inspiration often comes from a throw-away line that some panelist said, or some oblique observation on where the industry seems to be going.

This time last year I was working hard on Avelia Pet Adventures, little realizing that the kids-pet-MMO space was about to be overrun by big companies with big money. I’ve given up on that project now, although someone could still come along and buy the game from me (I’m not holding my breath, such has never happened before).

Last year, there was so much schwag in the exhibitors hall, I got a big box and stuffed it full of t-shirts, mousepads, and mints, and shipped it right from the show to my nephews in Houston. There were some nice t-shirts, but I can’t shop at these places for my wardrobe any longer. 🙂