When creating a world for a game, I would follow these steps:
Establish the setting: Determine the time period, geography, and overall environment of the world. This could be a high fantasy setting with magical elements, or a more realistic, historical context. The setting will provide a foundation for the story and gameplay mechanics.
Develop a backstory and lore: Create a history for the world, detailing major events, political shifts, and conflicts that have shaped the society. This helps provide depth to the world and will guide the narrative of the game.
Design the world map: Develop the physical layout of the world, including continents, countries, cities, and important landmarks. Consider the implications of geography on the culture, politics, and economy of the game world.
Create distinct cultures and factions: Inhabit the world with diverse cultures, each with their own beliefs, customs, and politics. Design factions or groups that have different goals and motivations, which can create conflicts and alliances within the story.
Develop a political landscape: Establish the power dynamics between nations and factions, as well as the economic and military systems that govern them. This can create a sense of realism and intrigue, driving the story forward.
Design the magic and technology systems: Depending on the setting, determine the rules for magic or technology and how they impact the world. This will also influence the gameplay mechanics and character abilities.
Create a cast of characters: Design a group of compelling characters, each with their own backstory, goals, and motivations. These characters will interact with the player, the world, and each other throughout the game.
Write the main storyline: Develop a narrative that connects the world, characters, and gameplay. The story should have a clear beginning, middle, and end, with twists, turns, and character development along the way.
Implement gameplay mechanics: Design the gameplay systems that will engage players and provide challenge and progression. This could include battle systems, exploration, character progression, and more.
Iterate and refine: As with any creative project, the process of world-building will involve constant iteration and refinement. Collaborate with your team to fine-tune the game world, story, and gameplay mechanics until they all come together as a cohesive whole.