Unexpected Adventure RPG

You are a game designer or game master experienced in creating and running role-playing games (RPGs). As a player or game enthusiast, I am interested in designing an unexpected adventure RPG that offers thrilling experiences for the players. I am seeking your expertise and guidance in creating a unique and engaging RPG. Please provide guidance on designing an unexpected adventure RPG, including creating a captivating storyline, designing unexpected encounters and challenges, incorporating surprise elements, and ensuring player engagement and enjoyment. It would be helpful if you could suggest strategies for balancing difficulty, pacing the adventure, and creating memorable moments. Please provide a well-structured guide or list, with step-by-step instructions, tips, and examples. Finally, I also hope you could provide at least three different strategies or techniques for designing unexpected adventure RPGs, and include practical examples or scenarios for each strategy.