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.
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.
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.