Since its creation in 1974, Dungeons and Dragons has been the most popular tabletop role-playing game. Recently however, its market share has been shrinking because of the release of its 4th edition. The 4th edition was an effort to capture a part of online gaming's action oriented market, but in doing so it moved away from its storytelling roots. Now the designers of D&D, Wizards of Coast, are looking to reclaim its position as the best of the TRPGs. The 5th edition of the game will have many challenges as new competitors have risen in recent years.
Wizards of the Coast is responsible for D&Ds; massively successful 3rd edition, and less than spectacular 4th edition. Wizards was acquired by Hasbro in 1999, and has some of the best talent in game design. As a company they emphasize story-telling, creativity, and art. Wizards also own many other games such as "Magic: the gathering", "robo-rally", and the Star Wars roleplaying game. Their experience in managing such a wide variety of games gives them a significant advantage over their competitors.
The primary competition for D&D is the game Pathfinder, created by Paizo. Pathfinder was only created as a reaction to discontinuation of D&D's 3rd edition. Paizo capitalized by filling the gap in the market for a TRPG with action and story-telling elements. Since its inception to 2012, Pathfinder has captured 38% of the market, which was even greater than the 36% of D&D. Simply amazing given that it never even existed before!.
D&D does compete against other TRPGs on the market. Games such as Werewolf: The Apocalypse, Call of Cthulu, GURPS, all have unique traits that differentiate themselves from D&D. Werewolf: The Apocalypse prides itself in its story-telling ability, Call of Cthulu its horror theme, and GURPS its incredible flexibility. However, all these companies target smaller niche groups, so it would not be effective for Wizards to compete with these companies for these players.