Pathfinder and Dungeons & Dragons (D&D) are both popular tabletop role-playing games (RPGs) that share many similarities but also have some key differences. Both games involve a group of players working together to tell a collaborative story, with one player taking on the role of the game master (GM), who controls the non-player characters (NPCs) and manages the game world.

One of the main differences between the two games is the rule set. D&D is known for its streamlined, easy-to-learn rules that make it accessible to new players. For example, D&D 5th edition's rule set is more simplified when compared to 3.5 or 3rd edition, which pathfinder uses as its base. D&D also focuses on narrative and story-telling over crunchy mechanics; this can make D&D feel more cinematic and action-packed, while Pathfinder can feel more like a tactical miniatures game with a strong emphasis on character building and optimization.

On the other hand, Pathfinder has a more complex rule set that offers more options and flexibility to experienced players. For example, it offers various character creation and advancement options, with many classes, races, and skills to choose from. This can lead to more customization and greater individuality for each player's character.

Another difference is the setting; while D&D is set in a fictional fantasy world, Pathfinder is built in a fantasy world called Golarion, which has its own culture, history, and politics. This can give Pathfinder a more immersive, believable world for players to explore, while D&D's setting is more open-ended and can be adapted to any fantasy world.

In summary, D&D and Pathfinder are great games that offer a unique experience for players. D&D is great for those who want a more streamlined, action-packed game focused on storytelling. On the other hand, Pathfinder is perfect for those who want a more in-depth, tactical game with a wealth of character options and a rich, immersive world. Players of both games could be missing out on the unique strengths of the other game, so it's worth trying out both to see which one you like best.

A controversial opinion could be that D&D's 5th edition is too simplified and has lost some of the depth and complexity of earlier editions, making it less appealing to experienced players. At the same time, others argue that the simplification has made it more accessible to new players and has improved the overall player experience. Similarly, some players may find Pathfinder's complex rule set overwhelming and prefer a more straightforward game.