Monday, October 20, 2008

What Half-Life 2 can Teach us About Game Design

Half-Life 2, as well as its episodic sequels Episode 1 and Episode 2, are as close to perfection as any game has ever gotten. If any game deserves a 10/10 score, these games do. In designing the games, Valve made every right decision it is possible to make. Basically, I LOVE HALF-LIFE 2. What's so good about it, though? What makes Valve such a master of the art of game design? Why, if you haven't played Half-Life 2 yet, are you still reading this?! GO PLAY IT!

Half-Life 2 is so amazing because it adheres perfectly to the Golden Rules of Game Design. Let's run through them, and see examples of when they work and when they don't.

Rule 1: Never Screw the Player
This one is first because it's the foundation of a solid gaming experience. Simply put, this rule means that the player should have a way to deal with any possible situation in the game. A player should never be in a situation where they are simply trapped and must re-load the level. A player should never be in a situation where they are attacked by an enemy and have no possible way to defend themselves. Basically, the player shouldn't feel like the game is unfair.

Good Examples:
If you do this one right, the player probably won't even notice. Take, for example, the practice of giving the player a backup melee weapon or melee attack. If the player is snuck up on, or runs out of ammo, they still need to be able to defend themselves. Another example found often in HL2: often there will be enemies that require certain weapons to deal with. Hunter-choppers require rockets; turrets often require grenades or antlion minions, and so forth. Valve makes sure to place crates with infinitely replenishing ammo for those specific weapons in just the right spot. This ensures you're never screwed when you reach a hunter-chopper, because you always have the ammo to deal with it.

Bad Examples:
Any time you died or got stuck in a game and felt it was just unfair, that's probably an example of a game that didn't follow this rule. Here's one off the top of my head: Killer 7. As you walk through the game on a predefined rail path, if an enemy appears, you need to switch to your gun and then shoot it in a weak spot. You can only move forward or turn around and walk in straight lines. You have no control over when you reload your gun, and enemies also tend to pop out at you in close proximity. If this happens, and you need to reload, you're simply screwed. You have no way to defend yourself properly. Another recent example is a fan-made expansion for Portal called Portal: Prelude. The opening level starts you in a small room, similar to the opening of the full game. When the portal automatically opens, allowing you to leave, you are greeted on the other side of that portal with several turrets shooting at you directly behind you. There's really not much you can do about it, and it's almost a certainty you'll die the first time you play that level. That's unfair, and it breaks the first Golden Rule.

Rule 2: Generally Follow the Pacing Steps
This rule is a little different, but it's just as fundamental as rule 1. Every good game follows this (along with all the Golden Rules) as a very general guideline to game pacing. First, most games are split into different sections. Sometimes they are split by setting, sometimes by gameplay, and sometimes they are only split by the Pacing Steps, but they all have to be split or they become repetitive. For a given section, the Pacing Steps are as follows:

A: The Establishment Step - Present the new setting, gameplay element (item, enemy, obstacle, etc.), or in some cases the game world itself, in a safe and clear way so the player sees what they'll be in for in this section of the game. Example: When you receive the gravity gun in HL2, you are presented with a small area full of objects to play around with, and Alyx gives you a small tutorial. Another example: In Episode 1, when you first see a Zombine (Combine Zombie), it is safely behind a window. You observe it grab a grenade and run at you, exploding itself. This reveals the new enemy safely, without explicitly telling you how to deal with it.

B: Basic Application Step - Here is where you have to actually deal with what was "established" in step A. You need to apply the new gameplay element, or deal with the new obstacle, or use the new item in a real situation, usually involving some element of danger (but nothing too hard yet). Example: After you get the gravity gun and play around with it, you're forced to detour into the zombie-infested village of Ravenholm. In this village, you're encouraged (not forced) to use the gravity gun to take down zombies in creative ways, including launching buzz saws to cut them in half. (bonus example! the buzz saw is introduced according to these steps too; you first see it stuck into the dismembered body of a dead zombie, hinting at its purpose - Establishment Step!)

C: Advanced Application Step - Now that you've dealt with the basic application of the new gameplay element or setting, it's time to get more complex. This step will usually demand that you use what you've just learned in concert with previous skills. This is where the game should get challenging. Some games follow the first 2 steps but fail at this one. Such games are commonly known as "not very deep." Example: When you're introduced to the buggy in HL2, you're forced to utilize the gravity gun to flip it over in order to progress. This step often lasts for an entire game, or overlaps later sections of the game. The gravity gun has new uses throughout the game, such as when you encounter turrets and must use the gravity gun to take them out. That's technically a new section, the turret section, but it includes a new advanced use of the gravity gun in dealing with the turrets.

After step C, a new section will begin for the next new gameplay element, unless of course you've reached the end of the game, or the entire game is made up of one large section. Many times these Pacing Steps aren't followed in a really cut-and-dry way, but any good game does follow them in some degree. If a game is based on only one major gameplay element (for example, Katamari Damacy), the entire game often serves as a section, but the 3 steps are still followed. When a game properly follows these steps, the pacing ought to feel good. The game will feel fresh at each section, and you'll constantly be challenged with new gameplay elements and settings.

Rule 3: Everything Should Feel Natural
This is a big one, and it deals with the little details in a game. In this case, "natural" might mean "consistent," or it might mean "realistic," but things shouldn't feel disjointed. It's hard to describe examples of this, because it really is the sum of details that make up the natural feel of a game. There are, however, examples of games that don't follow this rule. Some RPGs or adventure games, in which you encounter invisible walls, or small steps that you can't jump onto, take you out of the game. They remind you that it is, in fact, just a game, and it doesn't feel "natural." In HL2, every boundary in the game is defined by walls that clearly make sense in the context of the game world. If you reach a spot where Valve doesn't want you backtracking, you'll be forced to jump down a small cliff which will be impossible to jump back up. That feels natural and plausible. The environment is forcing you to keep moving forward, not anything arbitrary.

If a game follows these rules, it will be GOOD. If you can think of a bad game, chances are it breaks one or more of these rules, in some way.