How can one test if the difficulty is good or not. By "good" I mean fun, useful, or adds value. There is difficulty that is cumbersome or tedious. A simple example is doing a sequence of moves like a dance or just jumping up and down 1000 times. One is more difficult but the challenge has little value. I propose a test that compares systems of difficulty or a process of adding difficulty in a manner that does not bore the player but adds value to the game. A simple way to think about this test is to understand this idea: The game is interactive and real time. If that idea is accepted then the challenge must maintain this idea and also. I see more examples of bad than good when challenge is added the RPG genre. There is too much time spent configuring or using items in a frozen menu. Challenge should engage the player with the world not take them out of it. The challenge is not just to do with specific elements and npcs in the world, but can be a part of the world itself. These challanges immerse the player into the game's setting and reinforce the feeling that the player is not only seeing and hearing a new setting but can feel it and that this feeling immerses the player.
Vaguley put the bad way to add challenge to a game is to compound a simple task enough times to make things tedious. Two general examples of this in video games is when you have a swarm of endless enemies that are all easy to kill but the game keeps spawning them to add length to combat. I will note that some games are built around this mechanic like the top down arcade shooter Radien (which I think is a great game). In a similar fashion making enemies have more health to extend combat is also bad, this is know as a "bullet sponge." In these two examples the challenge being presented is one of patience. Just a mundane action done in repeititon. This is not a challenge that requires critical thinking.
Both fallout 4 and Skyrim include survival modes that add environmental challenges to the player. While the purpose of these modes is to produce a level of "realness" to the game ultimately is just annoying. In both of these games the state of hunger is given to the player that effects their strength. The mechanic to cure the hunger is to eat food. The end result is this mechanic requires to carry more items and open up your menu more. Fast travel is also removed from both of these games. Removing fast travel while takes away a convience and adds a mundane task of foot travel to the game. Now a playthrough that was 20% running around from place to place is 80% running around from place to place. The locations and bosses are the main attraction to these games not the hiking. The walking back the same way you came does not require any interesting critical thinking or new discovery. Removing fast travel is the environment equivalent of the bullet sponge, on one hand you have to shoot more on the other you have to walk more. All in all you want to play the game less. More of a stylistic critique is that the hunger and sleep mechanic in Fallout 4 also introduces an unrealistic effect. With Fallout 4's hunger mechanic you are disengaged from the environment and it becomes a new encumberance system because now you have to carry more food. Both encumberance and hunger in fallout 4 are systems that are constant annoyances. Encumberance has a decent realistic application being an attribute governed by strength. The idea you want to cap the amount of junk a character can carry because of the crafting mechanic introduces a knowledge challenge to the player to decide what they can and cant craft or how much the can sell. Hunger has no relationship with any attribute and doesnt serve any purpose but to make useless items more useful. The game is not more fun because I have to actually care about eating a radroach steak now. The interplay between eating, sleeping and disease truns the player into some kind of strange consumption being that needs to eat and sleep like its a full time job. It gets annoying and silly quickly. Realism is a double edge sword. We play games because we cant safely do whats in the game in reality, yet we need to have some kind of relationship to whats going on in the game for it to be an understandable experience. The game must have some relationship to reality. That relationship should begin and end with the exciting experience. If its not exciting quickly simulate it like fallout 3 gun repair. The death stranding story seems nice, but I dont need to buy a game to carry boxes.
Darksouls 3 provides environmental challenges that interesting and dont remove the player from the game. Instead these traps bring the player closer to the game. The poison lake, lava lake and other various arrow and gigantic crossbow traps are part of the scenery and part of the challenge. You are not removed from the game when these challenges effect you and you are called to take deeper awareness of the environment. You either avoid the challenge or prepare for the challenge or try to by pass it as fast as possible. There is also a creative tone to these challenges. In a way they are more realistic than the challenge of introducing hunger in Fallout 4 because these traps support a theme of the location and are not overdone. The traps are carefully laid out and become another enemy to fight as your are trying to get from point a to point b. On a side note the sub menu system and general experience of not having a pause menu in DS3 really means you are never away from the game. When applying a new challenge to a game there are some charactistics that can make sure it brings value to a game. A challenge that has multiple solutions rienforces the variety given to the player and generates a unique feel to the decisions a player has made. If an challnege can be implemented to have an instant effect and require an instant reaction by the player that is best. This keeps the player engaged with the game and makes their speed on twarting the challenge a skill to improve. This instant reaction compounded with unique sounds and visuals can add a little creative emersion to an obsticle that would usually just be something to avoid.
If I was to redo the hunger mechanic for Fallout 4 I would combine it with the endurance attribute, make it immediately effect the players feel of the character, and control how many times you can eat perday. These three things along with removing all the other sleep and disease stuff. If you combine it with endurance where the more endurance you have the more you have to eat to feel "healthy" then it instantly has an effect on how you plan your character. If you are tanky then you have to eat more or you can be frail but you dont have to worry about that part just worry that you can only take one bullet before a stimpack is needed. If a players hunger meter is below 50% they are slower and this would compound at 25% and 10% of the hunger meter. This would effect movement speed, melee attack speed and reload speed. A player would only be able to have 2 meals and 1 snack per day giving 75% and 25% of the health meter back. The player would have to sleep to reset the day. The hunger would decrease for every attack, something like .5% per attack. I would also implement an auto eat mechanic that allows you to just consume when you hit the 50% mark there by not removing you from the game. There are more details to flush out like what constitutes a "meal" and a "snack" but the point is to make it meaningful and interactive while trying not to interupt the player from the game. When making a trek you have to plan to know how much food you have and how far that will get you. In this case how dangerous the trek might be is important too. It is part of planing our your travels for the day and makes the no fast travel mechanic an interactive and immersive part of the play.
With challenge mechanics the rule is quality over quantity. Games should introduce a few very complex challenges that require instant reactions from players and add to the variety alreay given in the game.