
User-generated content
Do you want a lot of content but don't want it to come from a soulless algorithm? Encourage your players to create and provide new content for each other!
There are many ways in which you can do this. In the past, PC games have often come with a set of map editors and content creation tools some of the best maps in games such as StarCraft and Heroes of Might and Magic were made by fans. Empowering and supporting an active modding community can also be a valid solution for prolonging your game's lifespan and appeal. However, it can also be very time-consuming and expensive to run, support, and moderate. Therefore, it makes the most sense for big, premium games such as Fallout and Elder Scrolls.
Nowadays, the online architecture can enable player generated content to be immediately and seamlessly integrated into the core experience. We've got Super Mario Maker featuring thousands of great maps and the likes of Little Big Planet that let players create and share entirely new types of gameplay experiences that can play nothing like the main game. However, the quality of such free-flowing player creations is often questionable. Without proper moderation tools, as well as ways of promoting quality content, things can go south pretty quickly. As much as you'd want things to run themselves, such features will surely require constant oversight and inflate your game's scope significantly.
Maps and mods are great! Unfortunately, not every player wants to spend hours crafting content for others. Fortunately, there are ways in which you could make your players produce high-quality content unintentionally! All you need is to turn that content creation into a significant part of your game. In games like the mobile smash-hit Clash of Clans, player generated maps are used front and center for everything (apart from a relatively short and insignificant single-player campaign). The game has dominated what we now call a build and battle genre, a mix of a real-time strategy and a tower defense game. In these games, players build and upgrade their bases (carefully placing their defenses to protect themselves), recruit troops, and attack other players to take their resources. Incentivizing players to protect their resources drives each and every player to create a new, highly playable map for everyone else. Moderation impact is minimal for the developer, and since players are ranked and match-made against each other, the difficulty is properly maintained.