In Dungeons & Dragons (D&D), the term "Fiend" refers to any creature that is inherently evil and originates from other realms outside the material world, where the players typically adventure. Fiends come in various forms but are usually demons, devils, or other monstrous beings with a natural inclination towards destruction, manipulation, and chaos.

These creatures often serve as adversaries in D&D campaigns, challenging players with their powerful abilities and malevolent intentions. Fiends are known for their cunning, offering dark deals, and presenting complex moral dilemmas to players. They reside in the Lower Planes of the D&D universe, such as the Nine Hells or the Abyss, which are dimensions filled with torment and despair.

Understanding fiends in D&D 5e is essential for players and Dungeon Masters alike, as they frequently appear in adventure modules and campaign settings. When creating stories or encounters involving fiends, it's important to consider their motivations, which often revolve around gaining power, spreading evil, or serving a more powerful fiendish lord.

Fiends possess a range of supernatural powers, including the ability to cast spells, shape reality to their will, or summon other fiends to their aid. Their strengths and weaknesses vary widely, so preparing for an encounter with a fiend requires knowledge and strategy.

For new players, encountering a fiend can be a defining moment in a campaign, offering opportunities for heroism, sacrifice, and the struggle between good and evil. When dealing with fiends, players should be cautious, as these creatures are deceptive and their agreements are often fraught with peril.