Game difficulty is a very subjective topic, as many of the best-crafted games strive to deliver a balanced difficulty curve.

In an age where designers are attempting to attract more gamers with easier games, some of the best games move their difficult moments off of the critical path. Some games offer achievements for those that brave the hardest setting, while others hide the difficulty for the players to discover (see Kirby's Epic Yarn as an example of an easy game that hides its more challenging paths in optional, hard-to-reach areas).

However, there are games that throw the player into shark-infested waters from the get-go -- and that can be a good thing.

How Does It Work?

Ninja Gaiden Black and Demon's Souls are two such titles. Both games are considered by many gamers to be among the best out there, garnering numerous awards. One area that everyone can agree on is that these games are hard from the minute they start and never let up.

The first group battle in Ninja Gaiden Black can easily take apart a novice player, and many gamers couldn't even get past the first level. Demon's Souls was kind enough to give players a 10 minute tutorial... before introducing them to an enemy who kills them in one shot.

From the outside, this sounds unfair -- maybe even cruel. However, there is a method to the madness, and that method is "tough love."

Both Ninja Gaiden Black and Demon's Souls, from the very beginning, are designed around several key mechanics. With Ninja Gaiden Black it's constant movement, reading enemy tells, and knowing when to attack and when to move. Demon's Souls is similar, with the added mechanic of keeping track of the character's stamina, which allows them to block and roll out of the way.

If the player doesn't learn these mechanics at the start of the game, there will be no way for them to finish the game, as both games' combat models are designed around these concepts.

Starting the game at a higher than normal difficulty introduces the concept of "Darwinian Difficulty", which can be summarized by the motto "adapt or die." Button mashing doesn't work with either title, nor does standing still and holding the block button down all day. Both titles rely heavily on telegraphing strong attacks, cluing the player in that if they get hit, it could be fatal.

Putting players through a "trial by fire" does several things. First, is that the difficulty curve for a game like this is different from other titles. The following chart shows the differences:

Normal game difficulty starts out on the easy side and gradually gets harder. There may be a lull here and there, but for the majority of the game, the challenges will be getting progressively more difficult. The difference is that in a game with a higher starting difficulty, such as the games mentioned in this article, the difficulty curve looks like the green line.

Darwinian Difficulty starts out harder, and there aren't any lulls. However, the difficulty of the game doesn't curve up as a normal game. The reason is that as the player improves at the game, the game will becomes easier for them, lowering the curve over the time. This act of basing the difficulty off of the player -- otherwise referred to as "Subjective Difficulty" -- will be looked at later on in the article.

Darwinian Difficulty also forces the player to learn all the tools in their arsenal. One common pitfall of action titles is offering an elaborately-designed combat system that goes completely underutilized. Players will often rely on simpler actions (button mashing, for example.) This leads to two results: the player will find the game boring because it's not challenging, and they'll eventually face a fight where they don't know what to do, because they didn't explore the game's mechanics.

Games like Ninja Gaiden Black offer the player the majority of gameplay actions available from the start, which is one of the reasons why these games are so daunting for newcomers. Within the first level of the game, the player will be asked to make use of all the available gameplay mechanics. In a game like this, the gameplay doesn't change as much over the course of the experience as compared to other games. The player is not going to find an item or power-up that completely changes how the game is played halfway through.

How Do You Design For Darwinian Difficulty?

In order to design a game around Darwinian Difficulty, there are several considerations that the designer needs to keep in mind. First, in order to build a game around this concept, the game has to be predominantly skill-based. The reason is that in order for the player to be motivated to improve, they need to realize that they are the biggest factor to their success or failure.

Design-wise, there need to be as few abstractions as possible for the player to deal with. In a traditional RPG, the character's level and attributes determines who wins a fight. Darwinian Difficulty requires a specific type of challenge that RPGs don't have. Even roguelikes, which are known for their high degree of difficulty, don't fall into the category of Darwinian Difficulty. The reason is that the aspects that make a roguelike challenging are randomization and character attributes, not player skill.

The next consideration is that there still needs to be gameplay growth. If the player is doing the same exact thing from beginning to end, then the game will become boring. There are several ways to introduce growth, such as improving the character's abilities. In Ninja Gaiden Black, players can increase their maximum health and upgrade their weapons, which in turn improve damage output and combo durations.

New enemies and situations are the easiest way to implement growth, and they must be implemented in the design. The boss variety seen in Demon's Souls is one of the best, with each boss providing a unique challenge for the player -- such as the two-against-one Man-eater battle, or fighting the Old Hero boss, who is blind and can only detect the player via sound.

Even though there should be gameplay growth, there is a danger in adding too much -- which leads to the next consideration.

The player should not earn any upgrades or abilities that supersede player skill. Because the player's skill is the main factor in the game, giving the player something that undervalues skill can break the game. In Ninja Gaiden, the developers gave the player the ability to counter-attack after the first few stages. By timing their blocks, players could avoid all damage and deal it back to the enemy. The developers saw that this was making the game too easy and removed the feature for Ninja Gaiden Black, as they wanted the player to see that constant movement was required to win.

That is why health upgrades are the safest bet; they give the player a greater buffer between life and death, but don't get in the way of player skill. Many of the bosses in Demon's Souls can kill the player in a few hits; having a greater health bar may give the player a little more of a chance to survive, but if the player doesn't learn how to avoid the attacks, they'll lose no matter what.

The flipside of this consideration is that you should never change the game in a way that negates previous mechanics and skills. Getting rid of a mechanic that the player spent time learning and improving at will make the player feel like that wasted their time -- and this hurts the design.

You can find an example of this in Bayonetta. At the start, the player is introduced to the concept of "Witch Time". By dodging attacks at the precise moment of impact, the world slows down for the player, allowing for an increased window for attack. Slowing down time also allows players a chance to hit enemies which are more agile then the player.

However, halfway through the game, the designers introduce "gold-plated" enemies, whose attacks will not trigger Witch Time if the player dodges them. Because Witch Time is one of the only two ways of avoiding damage for much of the game, players are left severely handicapped while fighting these enemies.

The last consideration is that even though these titles are harder compared to other games, it is alright to throw the player a bone by implementing a difficulty selection system. Granted, an "easy mode" in a game with Darwinian Difficulty is still harder than in normal games, but it does give less experienced players a chance to "pump up" before trying the higher settings. Ninja Gaiden Black featured multiple difficulty levels, ranging from very easy to experts only.

Ninja Gaiden Black

It's All About Defense

Putting all the considerations together, we can take a closer look at Ninja Gaiden Black and Demon's Souls, and what makes them challenging.

Ninja Gaiden Black's enemy design is built around forcing the player to keep moving. The way the designers did this was giving just about every enemy (including bosses) a grab attack. Grab attacks are unblockable and do immense damage. Some grab attacks are telegraphed, while others are used immediately once the player blocks a few attacks by an enemy.

The sooner the player masters the dodge roll, as oppose to regular blocking, the better. As the game goes on, enemies will become faster, and the challenge of "sticking and moving" will become greater.

The challenge culminates in two ways. First are mirror battles. Players who are skilled enough to play on the higher difficulty levels will run into battles with their doppelganger. The doppelganger will use one of the player's weapons, and all the same tactics and techniques the player has, and it will be up to the player to deal with an enemy who is their equal.

Second, regardless of the difficulty level, before the player can fight the final boss, they will be put through a gauntlet of boss fights and arena battles. Taking too much damage early on will leave the player in a bad position to finish the fights, forcing the player to get as close to a "perfect run" as possible. On the harder difficulty levels, the gauntlet is extended with more battles and bosses, including one that was never shown to the player until now.

The unique boss is easily one of the toughest enemies in the game, as mastering the timing needed to dodge attacks is required for both offense and defense. Her main attack is a beam of energy that can only be avoided by dodging just before she uses it. To complicate matters, only attacks issued after dodging her moves will connect. Getting through this fight without a scratch requires "master level" play, and is a sign that the player is good enough to finish the game.

Moving onto Demon's Souls, the game also requires players to understand all defensive options available. To avoid damage, players can block attacks, dodge out of the way, or attempt a riposte to counter. Blocking and dodging will consume stamina, which also affects how often the player can attack.

When the player blocks, the strength of the shield will determine if any damage "leaks through". The stronger the attack, the more stamina is drained. Dodging uses more stamina with each individual use, but its cost remains fixed. The other benefit is that dodging guarantees that the player will not take any damage, and it can be used to set up a follow-up attack from the enemy's blind side.

The final option is the riposte, which requires the player to time the move just before impact. Pulling this off uses no stamina, and the following counterattack will do extra damage. Missing the timing will punish the player -- the full hit from the enemy will connect.

The toughest lesson for the player to learn is to master dodging and only use blocking as a last resort. Blocking should be avoided at all cost against bosses and larger enemies, as the stamina drain is intense. When fire and magic attacks are introduced, normal shields will not absorb either damage regardless of their strength, signaling the player even more that dodging is needed.

Like Ninja Gaiden Black, this lesson culminates with a final battle. The last boss in Demon's Souls does immense damage with each attack -- along with a major stamina drain if the player blocks. Taking its full combo attack is fatal. One of its most frequently used attacks is a dash that requires the player to dodge just as it reaches the player; dodging too soon or too late will result in the player getting hit.

The boss also has two powerful attacks that it uses rarely. The first is an explosion with an area effect that is fatal to all but the most heavily-armored players. The only options available to the player are to get as far away as possible, or to hit the boss, canceling the attack.

The second is a close range telegraphed grab. If it connects, the boss will permanently remove one experience level off the player. Beating the boss requires players to have mastered dodging and fully understand when there is an opening to attack. Both games are clear examples of Darwinian Difficulty and highlight the advantages and disadvantages of the design.

The Advantages of Darwinian Difficulty...

There are several advantages to Darwinian Difficulty. Let's return to the concept of "Subjective Difficulty". Because the majority of the mechanics are available from the start, as the player improves their skills, the game should become easier the longer they play.

The reason is that all the enemies, bosses, and situations are based around the core mechanics. The only changes that happen in the game are the encounters the player will face.

By learning the core mechanics of the game, players will learn to adapt to the new challenges the designers throw at them. Sections that gave the player a lot of trouble at the start of the game should no longer challenge the player once their skill has improved.

Developing the game using Darwinian Difficulty gives the designers a greater understanding of the skill level of the players, allowing them more freedom with their design. In a normal action game, the designer can have a hard time determining how good the players are at specific points in the game.

One player may have mastered all the combos by the halfway point; someone else may still be button mashing. With games designed with a Darwinian view, the designers know that anyone who got past the first level knows all the mechanics at hand, and can design around that.

The other advantage is motivating the player. Overcoming hardships or challenges brings a sense of a satisfaction. That sense of satisfaction can be felt by gamers who got through a game by their own skill. That satisfaction is a great motivator, as it is intrinsic to the player.

Replayability is another plus, because of the high degree of skill required; coming back to a game with Darwinian Difficulty after a long time can be a fresh experience. Similar to how if someone lifts weights, then stops for a long time, the muscles will atrophy, requiring the person to start small again and work their way up. This can also happen with games based on Darwinian Difficulty. Someone who beats the game, then stops playing for several months, will come back to find that they'll have to relearn those skills again.

Demon's Souls

...and the Disadvantages

With all this said, however, there are a few problems with Darwinian Difficulty that the designer has to keep in mind. First, is having such a high degree of difficulty early on hurts the appeal of the game. Games these days are being designed around having as much appeal as possible, which in this case means having a lower difficulty. A game where the player can die at any moment is not something a lot of people enjoy. Demon's Souls and its sequel, Dark Souls, may have created a lot of buzz, but they aren't truly mainstream hits.

Second, requiring the player to improve their skill is a great motivator, but there is a risk involved. The concept of "Subjective Difficulty" is just that: subjective. A challenge that one player breezes through without any effort can be a brick wall for another, stopping all progress. Losing a game because of issues with the design is easy to take. Losing a game because the player themselves was not good enough is a harder pill to swallow.

Getting completely stuck in a skill-based game is easier than in an RPG, due to gameplay abstraction. With an RPG, the player has other options of getting out of a tough spot, such as grinding levels or buying better gear. In a skill-based game, however, those options are not available, forcing the player to keep trying until they get past the section.

In this scenario, it's quite possible that that the player will get discouraged and stop playing. Stopping because of a brick wall will leave a bad taste in the player's mouth that will discourage them from playing again -- or outright quit the game -- which can leave a negative impression for future games from the developer.

Darwinian Difficulty is a hard mechanic to design around, requiring the designers to put in extra time fine-tuning the gameplay. The design is less about creating an imbalanced experience, forcing the player to climb out of a proverbial pit, and more about giving the player all the tools they need to succeed. Whether or not they'll be able to use them, however, is the big question. When designers successfully pull off the balance of difficulty, players will get an amazing experience few games these days deliver.