In every single-player shooter and most adventure games, there is some progression in player strength. Most commonly, the player gains access to new weapons, or more health, or similar upgrades. In designing a game, how you introduce these upgrades is very important. I’ll work on breaking it down as much as possible and covering every element I can think of while giving my opinion of what works and what doesn’t, but because this article turned out much, much longer than I originally thought it would, I’m going to cover this in a few parts. Bear in mind, I won’t talk about role-playing games (either first-person or otherwise) such as Fallout 3, the Elder Scrolls series, or more conventional RPGs; mostly just shooters with upgrade mechanics.
There are two kinds of upgrade pacing, but by far the most common type is a linear progression, meaning as you go through the game, upgrades (most commonly weapons) are slowly introduced to you. The earliest shooters, from Wolfenstein 3D to Quake 2, did this with just weapons, but other games do introduce more than that kind of upgrade. Probably the best example of this would have to be Warhammer 40,000: Space Marine. It didn’t just give you new weapons; it powered up just about every aspect of your character, and all at specific points of the game. Additionally, it gave you introductions as to what each upgrade was and the capabilities of each new weapon, so you knew what you were getting and had ample opportunity to test it.
Easily the best feature of linear progression is that it’s a lot easier to balance the game around. In Space Marine, the developers know exactly what upgrades and weapons the player will have at any particular point in the game. This is especially valuable if your game has an increasing progression of monsters, as well, where new, more powerful varieties of monsters appear as you move through the game. Some games like Halo and Crysis try to take this further by limiting you to a certain amount of weapons you can carry at a time, so you wouldn’t have this one weapon that could make this encounter too easy. Using a limited-weapon mechanic for balance like this is not something I agree with, but that’s something for another article.
The major problem with a strict linear progress (As in Space Marine) is that it reduces the replay value, because it’s always going to be the same progression each time you play. Games like Doom and Duke Nukem 3D, however, weren’t particularly linear; they had some more advanced weapons stored in secrets early on, so you could jump ahead of the curve. For example, in the first episode of Doom, there was a rocket launcher hidden in a secret in the third map. Otherwise, you might not get one until the seventh (though ammo was limited before, and even after that). With a more lenient progression, it can add replay value because the player might be able to jump ahead of the curve. This does come with its own benefits and problems, but I will talk about hiding items of progression in secrets in the third part of this series.
Speaking of Doom, in the earliest shooters from Wolfenstein 3D up to Quake, if you died on a level, you restarted that level with just your default weapon (usually referred to as pistol-starting, because the default was usually the pistol). This meant that the developer had to consider another dimension in the progression; whether the player came from a previous map, or whether he just started this one. In the more contemporary style of games it’s not an issue, but if that is a mechanic you want then this is something to consider. Usually this goes with a more arcadey style of map design, like those aforementioned games.
Another variation on the standard linear progression are games like Red Faction: Guerrilla, where new weapons become available at certain parts of the game, but aren’t simply handed to you. The player might possibly miss a weapon depending on how the game is laid out (I never found the Rail Driver in Red Faction: Guerrilla, for example), but I think that more open-world games (Crysis 1, Red Faction: Guerrilla, System Shock 2) work well with this more than other variations of linear progression.
While most of what I talk about is specifically with regard to single-player, several multiplayer shooters these days use a form of linear progression with an experience system to make players more powerful. Most Call of Duty titles (which have become the model for this kind of multiplayer progression) and even Space Marine did this, where they give new perks and weapons that are just plainly more powerful than the earlier ones. I really hate this idea, because it gives some players flat out more damage because they have been playing longer. There’s really no worse idea for a game than to punish a potentially decent portion of your audience just for not being part of the first group to play it. Space Marine tries to get around this by letting you copy the equipment loadout of the previous player who killed you, but when you have mechanics like that, then why do you even have the progression if you can do that anyway? It also starts feeling like hard work to get a weapon you want, and when a player plays a game, he doesn’t necessarily want to feel like he’s doing work; he wants to have fun!
This is the most basic version of upgrading the player. He gets a certain way through the game, he gets something new and useful, he fights more powerful things with it. I think it goes very well if your game has an increasing difficulty curve and a matching progression of monsters. Quake 4, for example, keeps introducing new monsters along with new weapons far into the game. Usually I like when a game introduces a weapon or some other upgrade that counters (even partially counters) a new monster after introducing the new monster and showing how great a counter for it would be. While it is the most basic method of upgrading the player, I think linear progression can work the best. It’s simpler to implement and often makes the player feel like he’s progressing through a game.