What is an optimum failure rate that will keep people coming back to my game?

Question

I'm guessing some research has been done into this but I can't find much information. The question might be a bit too vague in itself as it depends on so many other factors.

I'm developing a puzzle game that I want to be challenging, but not so challenging that users don't bother coming back to try again if they fail. I'm assuming the shorter the game length to more willing a user will be to try again.

For example, if a level takes an hour with a 95% failure rate, I suspect that many users wouldn't bother trying again after a couple of failures. But if a game takes 30 seconds then they'll probably keep trying again until they succeed.

I'm wondering if anyone has, or can point me in the direction of information that offers guidance on this aspect of game development.

Answer 1

There are probably exceptions to this, but as a thinking-aid, I theorise that failure severity, decision rate and responsibility should correlate. When one increases, players expect (and tolerate) higher levels of the other two.

Some examples (high to low intensity):

Super Meat Boy and N have high severity (much of the environment kills you on contact, forcing a level restart), but they curb frustration by allowing a high decision rate (short, minute-long levels, immediate respawn) and making the player fully responsible for failures (determinism, visual and auditory cues on death, predictable AI, highly polished controls).

FTL has much longer play times (up to a few hours total, with save points at will) and retrying is hence a larger undertaking. However, the average move won't doom you (your spaceship has a health bar, you can replace lost crew) and player responsibility for failure is likewise lower (large random factor).

At the low-intensity end of the spectrum are games like Monopoly or poker. Players make fairly infrequent decisions in long sittings, there are large random and human factors involved and most choices have a small influence.

Note that speed has no part in this. I'd argue chess is a high-intensity game, despite being slow: It has a high decision rate (both players are constantly making observations and decisions even during each others' turns), high severity (a badly considered move may decide the game at any point) and high responsibility (determinism, simple controls, lots of thinking time).

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Indeed there are differences in player demographics in what intensity they prefer: NES players were pretty darn tolerant.

When a game like I Wanna Be The Guy introduces itself as "nail-rippingly difficult" or when you download Dwarf Fortress and realise the ridiculous level of detail, all of that filters the audience and primes difficulty expectations high, all before actually playing.

Answer 2

People come back to a game if they're entertained by it. That's what you need to do, in short. Entertain players. Failure itself does not cause people to run away. A boring game causes people to run away. Rather than concentrating on mathematically predicting how many people will fail a particular level, concentrate on finding ways to make it so they're motivated to jump back into the action after failure.

Motivation is probably the most important aspect. A motivated player will spend days trying to tackle the same level, if that's what's needed to win. Make sure you're showing the player how close to the goal he is when dying, and how awesome the rewards will be. If there's no motivation to win, the player is likely to abandon your game when he starts dying. A game that does not motivate the player is not entertaining to play. Puzzle games motivate their players with unlockable powerups that clear the board yielding bonus points and whatnot. Shooters motivate the players with new levels, new weapons and new enemies. RPGs motivate players with more awesome enemies, level ups and loot. A good motivator is a list of achievements that the player can earn. Make the achievements be numerous and only a select few very hard to earn. There's nothing more motivating to unlock all achievements than seeing you've already unlocked 98% of them.

Another very important thing is to make it extremely easy for the player to get back in the action after his failure. The higher he has to climb after falling, the more probable it is he'll give up and do something else instead. This can be achieved in multiple ways. Short levels, allowing quicksaves at any point in time, many checkpoints, turning back time to repair your mistake etc.

Balance the difficulty properly. Difficulty spikes are unexpected and ugly to deal with. Make that difficulty slope as smooth as possible. Make sure the difficulty comes only from the game's mechanics, not from the interface with the player. If a game is difficult to control, the frustrated player will surely abandon it.

For some types of games you can go with some meta game mechanics to increase the player's motivation and keep him playing:

Socialization is an important aspect to the casual crowd. Get your game to use stuff like Facebook posting, and let the player boast about his victories. Let him see other people playing better, and he might just want to play more in order to take them down from the top positions.

If you're seeing hype building around your game, make sure people are focusing on the core aspects of your game. You know Dark Souls is hard as hell because that's what everyone says about it. You know everyone failed most of the time while playing it, because people take pride in finally beating the game and tell the story. Surely joining the crowd and doing better than your fellow players is motivating in this case.

Answer 3

There are multiple factors to consider (as always). As you posted a link to your game, I also want to talk about the specific implications for your special case.

1. Player responsibility

This was already explained quite nicely by @Anko. If the player feels like he is actually responsible for his failure and has a chance to improve via the knowledge he gained by failing, he is more tempted to do so.

With games that contain somewhat randomly generated content like The Binding of Isaac and probably your puzzle game, that is quite a hard goal to accomplish on a higher difficulty. On most of such games, you can fail very hard or win very high without actually playing better or worse. You could of course go with hand-crafted levels, or use the method I'll explain in #3.

2. Instant restart

Not necessarilly a huge point, but definitely important: Enable players to restart instantly. If they feel like they messed up or did indeed fail a level they need to be able to restart in a moments notice so that neither gameplay is interrupted nor thought is distracted. With all skill-based games, you are learning by doing, and the less time you spend doing in a session, the less you learn in a session.

Additionally, interruptions can be frustrating. Especially with the short attention span your game gets on a mobile platform, make every second count. A very good example is Super Hexagon where you can restart so instantly, it doesn't even always feel like failure. As a counter-example, Space Run has a 5-10 second cutscene and requires you to redo your ship configuration on every restart, which is very critical as it is a difficult, failure-base game.

3. "I nearly did it!"

As an addition to player responsibility: you can fool the player, which isn't necessarily a bad thing.

You would need a somewhat dynamic difficulty level which makes the game a bit harder or a bit easier depending on how the player does at the moment. This can emulate the feeling of being in control, but you have to be careful to not overdo it. In your case, if you detect the player is running behind, give him a few more words so he can catch up to the goal and barely make or not make it.

This way, if he fails, he will be more compelled to try again, or (and this is where the success of Candy Crush lies), make him buy a few extra moves or extra time to complete the level. Extra Credits has an excellent video on the topic. This would of course be an excellent hook for monetization.

4. Rewards

Only indirectly related to difficulty, let players unlock achievements or trophies, show them cool animations for good combos, make them feel like they're working towards a goal even if the odds aren't quite in their favour right now. Most First-Person-Shooters use this principle these days and they have good reason to do so, as they operate in a high-frustration/high-reward field.

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There they are, my two cents on the topic. Keep in mind that you may want to question my reasoning to let your own thoughts and ideas emerge.

Answer 4

A very important aspect of a game is what Warren Robinett called "controlled randomness". If you don't want a level to have a particular fixed solution, ensure that the level of difficulty will not be unreasonably affected by the random number generator. The game should be designed so that a someone who plays perfectly would have a 100% chance of completing every level regardless of whether the random number generator was "favorable" or "unfavorable", but a certain amount of skill would be necessary to have a significant chance of winning no matter how "favorable" the random number generation happened to be.

A major source of frustration with some games is the fact that there can be times when e.g. a player cannot possibly win unless the random generator produces a particular sort of tile, and it's not uncommon for the player to run out of moves before such a tile appears. If the design of the puzzle is such that e.g. the player will have 50 moves, but a key piece won't arrive until move #46, and thus a player must figure out how to use the first 45 moves to set things up to allow a five-move win once that piece arrives, then tell the player that. Make it clear that the failure of the needed piece to appear within the first 45 moves is not a result of "bad luck", but rather represents the essence of the puzzle. A player who thinks the piece in question is simply "rare" might go out of his way to ensure that he's always in a position where he would be able to use it if it arrives, even though such a strategy couldn't possibly win if the piece doesn't arrive before turn #46. By contrast, if the player is informed that the piece will arrive precisely on turn #46, then the player will have a much better idea of what's necessary and be able to work much more productively to accomplish it.

Answer 5

Causing people to fail levels just so you can have them come back and try again is a recipe for getting frustrated users who not only don't come back but leave negative reviews about your game.

It's been tried, it's been done, it's ugly. Games where people get hit by random events that kill them off without any reason flowing from gameplay are NOT crowd pleasers.

Rather you should make your levels hard enough that they can be completed by a player with a decent but not stellar level of skill, and have them develop that skill by making levels progressively harder as they travel through your game. First levels should thus effectively be a tutorial.

Levels should also not be so long that people get bored and give up, thinking you're just making things impossibly hard because you can't be bothered to create a well leveled game experience.