Save System Design pt.1
Sunday, September 25, 2011 at 9:09PM It's difficult to find a video game these days that doesn't save player data in one form or another. Along the same lines, nearly all games with campaigns, single player modes, or story modes feature some kind of progress saving feature. In general the functions of saving and loading fall under the umbrella of difficulty design. In some ways, adding or taking away saving options does not affect the difficulty of gameplay challenges. Rather, it changes the flexibility that one can bring to the challenge in terms of taking breaks and reducing repeated attempts (elements that are outside of the challenge itself). With advancing technologies for console and handheld gaming, save system design is more complex than ever for more games. We now factor in portability and short play sessions, continuity with storytelling, difficulty, repetition, feature expectations, exploration freedom, the mental state of the player, and more. The following article will examine these considerations in detail.
We commonly think of saving and loading data as a player initiated function in video games. Technically, computers are constantly writing, reading, and deleting data. But from a game design perspective we can think of save system design as a combination of 3 main actions; save, store, and load. The facets of save functions include whether the game auto-save, the action is player initiated, what data is saved, when the player can save, and other grouped functions. Store options include how many slots are available and whether the player can copy, delete, or import/export the file. And load options are whether the game loads the data automatically or not, when the player can load, and any grouped functions.
As is my custom, I like to ground all design discussions with a look at Super Mario Brothers for the NES. At first, I thought that only the high score was saved to the NES cartridge. After I received a "game over" I had to start the game over from World 1-1. But SMB actually does feature a save system. Apparently, if you hold the A button and hit start, you can resume progress with your score reset on the first level of the last world you visited. This handy little feature saves your progress automatically and temporarily. In other words, the game doesn't store the information in memory so that it can be loaded after the system is reset.
Ignoring this simple and somewhat secret option, we can consider how players have responded to the difficulty design of Super Mario Bros. In my mind, before learning the save trick, I felt that SMB was a surprisingly challenging game. If I didn't take the warps and farm 1ups using the infinite Koopa shell trick, I really had to focus on good strategies to survive all 8 worlds. Thinking that a "game over" meant "start over" every coin became a worthwhile investment. In this way, a greater emphasis was put on collecting coins to earn extra lives, a well tuned suspended element in SMB's design. Restarting a game from scratch at a game over screen is about as harsh a pentalty as it gets. Older games like Super Mario Bros and roguelikes commonly have such a design. It seems like the biggest potential drawback to the lack of a save system is being forced to replay levels one has already beat. For SMB I see this as a positive thing.
Playing through levels again emphasises the emergent possibilities of a game's level design. Think about it this way, if every time (or even many of the times) you play a level the challenge and therefore the experience is different, you have to play the level more and more to appreciate this quality. After playing World 1-1 and 1-2 dozens of times, I formed a routine which included grabbing all of the powerups, uncovering all the secret blocks, and sliding down every possible pipe. Basically, I had my winning strategy memorized. However, the more I played each level the more I realized just how varied the challenges could be mainly due to SMB's layered level design (counterpoint). The interplay with the enemies and their multi stage threats, the destructible environments, the secrets, the coins, and the powerups are designed to interact with each other so that player actions ripple forward to create hundreds of different challenges and scenarios. Even on my 100th trip through 1-1 I've found traps that were never apparent to me before that were triggered by the subtle changes in my actions.
Furthermore, just beating a level or completing a task does not mean you have mastered it. Like with most writing, films, music, or other pieces of art, there's more to investigate, learn, and understand than one can ever experience initially. So, replaying content is something I appreciate because it helps me enjoy it better. For a game with a strong story focus, I can see why replaying levels could be irritating. Imagine reading half way through your favorite book and then being forced to read through the book again from a previous chapter. Rereading a section before you get to the end of the story may seem jarring because of the linear, forward moving progression of the story. Then again, don't you reread words, sentences, and paragraphs when you're confused about something? When you're watching a TV show or a movie, don't you pause and rewind when necessary? Isn't it more important to understand as you go along instead of push ahead especially when you move at your own pace? For these reasons, being forced to re-experience story content doesn't really bother me.
I don't see replaying a level or a challenge as a bad thing at all. This is not to say that I don't get tired of replaying a level at some point. Ultimately, I understand that most video games are learning systems where increased skills are required to overcome later challenges. This means that I am likely to come to a point where building the necessary skills requires replaying levels and challenges. This also means that building these skills may take time, rest, and refection. At these moments repeated attempts may only frustrate the situation. For these reasons, what I want may be at odds with what I need.
Since Super Mario Brothers, SMB: Lost Levels incorporated the secret load feature as a clear menu option. In SMB2 a game over reset players all the way back to the beginning of the game. And SMB3 resets players back to the first level of the world they died on. From Super Mario World and beyond, players can save their progress and work to unlock everything the games had to offer. With each change in the save system design, the way players could play the game changed. Also, with each change, the game designers at Nintendo adjusted the rest of the game as well.
So, from Mario's "old school" auto-save, load only, single (temporary) slot, in part 2 we'll look at the other extreme of save system design.
Reader Comments (9)
Great article! I'm glad you mention roguelikes; they're an interesting case, since the length of a single game requires a save / load function (just not a *reload* after you die feature). Most of the admittedly few nethack players I know will back-up the save files the game creates so a game can be resumed after being closed, and then restore those back-ups after they die. It sounds like these jury-rigged saves aren't far off from being genre convention.
I find this interesting for two reasons. First, it's a lot of work to make these backups compared to a quick-save button. Second, anyone that does it knows that they probably shouldn't. Combined, these drawbacks reduce the player's reliance on the feature. ... Actually, this sounds very similar in practice to the SMB hail mary button.
This may be something you address in a later part, but I think the appropriateness of a save system relies on the number of unique paths that will reasonably branch from that state. In nethack, for example, your actions after reloading one of these jury-rigged save files will generally help you to find an optimal path forward. In a roguelike, optimal can still mean doomed, but still, subsequent attempts will give you the chance to correct your mistakes. Games with regenerating health allow save states to greatly reduce the number of interesting and unique paths through a game; if you know on a reload where the 'tricky' part is going to be, you can wait and regen health to return to continue from an optimal state. This merges all sub-optimal paths into the optimal path from that point. Roguelikes use hunger to limit the usefullness of these attempts, but there will still be an 'optimal' solution by factoring in hunger rules.
SMB avoids this converging-states problem by not having regenerating health in the first place and, as you said, the effect of its level design means that you generally can't rehearse a save file repeatedly to find an optimal solution when it is so difficult to finely time your actions to leverage determinism.
@ Wes Paugh
Great comment.
I like how your example shows that even without a built in option, some gamers will go through great lengths to acquire save-security. I know how hard it is to lose in a roguelike at the very last level. Of course, these kinds of let downs are what I signed up for when I started playing Shiren.
Looking at save system design in terms of unique paths, emergent possibilities, and self teaching is a good way of thinking about the issue. I do plan on addressing these points later.
Be careful thought. Save system design is closely tied to difficulty design which is connected in part to the other facets of a game's design. I'm not sure we can say outright that regenerating health reduces the number of interesting and unique paths in a game. But I see your point in how the player experience will be more convergent with such elements than.
Optimization is also a pretty meaty topic that is difficult to use in an argument. Like you said, there will always be an optional path given full knowledge of the challenge at hand. Fortunately, interplay and consequences that ripple forward are great design tools to keep experiences varied.
Hold on, I think you're jumping ahead a bit here. What about the games prior to Super Mario Bros, where you didn't even have a continue option or in some cases, even an option to save high scores?
Also, your TV example seems flawed, most people don't rewind TV shows or such like, they watch them 'live' so to speak and have no option to do so. Same with movies at the cinema.
On another note, it could be interesting to look a bit more closely at Super Mario World's design, since it only lets you save after ghost houses, castles and fortresses (at least until you beat the game), and this limited save system was carried over to the New Super Mario Bros games. You've then got as a step up from this the auto save after each level (see Super Mario Land 2, Yoshi's Island, Wario Land and all 3D Mario games).
Also, you should cover the early Zelda games where saving increased the death counter, and you got the save prompt when you died. That was an interesting mechanic, and I think it was in one game with different endings, meaning you had a choice between never saving or seeing the 'normal' ending.
@CM30
I didn't say that I was starting at the beginning of video game saving history. I'm picking examples carefully to show a range of design styles. And it's only part 1 in the article series.
"Most people" eh? Got any data for this? Of course people watch TV/movies live when they don't have a choice (no DVR/in the theater). But the question is.. what do YOU do when you do have the choice? I've always paused and rewound if I missed something I thought was important.
More examples to come of course.
By most I mean that most people I know, even with the choice tend not rewind TV shows or the like. I'm not sure why, it's just no one ever seems to think to do so. I know I don't.
I don't have any hard data either, but I have to stick with CM30 here as well.
I don't rewind TV shows or movies, whether at home or not, and I don't know of anyone else who does either. Even when an on-screen conversation is interrupted by some loud noise in the real world, I notice strong resistance to breaking the flow of the movie or show and rewinding, even when some part is missed completely.
This effect is also stronger when watching with a group. I'm pretty sure people don't like to rewind. :p
@ axcho
What about the TiVo promise... record, pause, and rewind live TV. Somebody has to be using the feature, right?
Well, if you don't remind the show, do you or anyone you know ask anything like "what did he just say? What just happened?" If so... that counts.
That's a very interesting point you bring up about how replaying levels exposes the emergent gameplay, and it certainly gives a good insight into tightly-scripted modern games like Call of Duty. These games generally have checkpoints scattered liberally throughout, and as a result you rarely replay sections and are therefore are less likely to notice how little variation the AI displays.
However, this completely falls apart if you play on Veteran (the hardest difficulty setting). It becomes a memory game in which you move from safe-spot to safe-spot, memorising down to the pixel exactly where grenades are going to land and how many times the enemy will respawn before you can advance.
@CM30
I agree that TV was a poor example, but the book analogy was sufficient to get the point across.
@ Crowbarska
Emergence is so crazy in Super Mario Bros. I just beat the game from start to finish on hard mode playing every level. There are so many little emergent differences that caught me up in the funniest ways. I've been playing and studying this game since I was 3 years old. And I'm still finding new challenges and scenarios.
Some new games like COD are designed very limited. I generally dislike such level design and difficulty design. Even before I see through the linearity, I'm not a big fan. I guess these games are just like modern rail shooters like Star Fox. But they can be a lot more confusing.
I guess people have gotten out of the habit of asking "what happened" when watching tv/movies because they're generally watched in a social setting. Little kids do it all the time. When they miss something or didn't understand why everyone is laughing they ask. I still ask question too. hmmm.