Recommended by @Helgard
99.9% of this forum is dedicated to Game Development. That's all well and good, but what about Design?
I've spent the last year ignoring Game Design Theory.
The thing I've personally struggled with the most as a young developer is making a game that's fun to play.
Feel free to post your opinions, knowledge, what you've learned over the years, as well as any links to good, solid information out there on the Internet to help us all grow as Game Designers.
Extra Credits Game Design video series on Youtube -- 274 videos!
Craig Perko's "Concrete Play" video series on Youtube -- 15 videos
I'd like to share some more resources to assist in Game Design...
Fantasy name generator - Names, Locations, Descriptions
Chaotic Shiny - Names, Locations, People, Culture, Religion, etc.
The Big List of RPG Plots
The 36 Plots
Plots - TV Tropes
Ideas for creating Plots
Fallacy - Wikipedia
Logical Fallacies - All The Tropes
Tropes of Legend - All The Tropes
Deal With The Devil - TV Tropes
Logical Fallacies - TV Tropes
Three Hundred Mechanics
What is fun?
The Eight Kinds of Fun - Can you incorporate all of them into your game?
Roleplaying Tips - Written for a tabletop Dungeon Masters - helps to keep your players entertained, having fun, creating challenges, etc.
Make RPG Enjoyable - wikihow
Seeking Solis - the City of Solis RPG resource archive
Making different weapon types feel unique? - A discussion on Gamedev.Stackexchange about weapon types...
If your shotgun deals 10 damage every 5 seconds, but your pistol deals 2 damage every 1 second, what's the point?
Envato tuts+ is another great Game Design website I just found, with articles such as...
"5 Approaches to Crafting Systems in Games (and Where to Use Them)"
"Making AI Fun: When Good Enough is Good Enough"
"Numbers Getting Bigger: What Are Incremental Games, and Why Are They Fun?"
"How to Incorporate Satisfying Death Mechanics Into Your Game"
"4 Ways to Teach Your Players How to Play Your Game"
This website has it all.
- Mechanics, Discussions, Concepts,Difficulty, Length, etc.