Complex sentence: While transitioning from Advanced Dungeons & Dragons 2nd edition to Dungeons & Dragons 3rd edition, Wizards of the Coast acquired its rights and opted to let Alderac Entertainment Group continue publishing second-edition material for the "Legend of the Five Rings Roleplaying Game" system.
Split into simpler sentences: While transitioning from Advanced Dungeons & Dragons 2nd edition to Dungeons & Dragons 3rd edition, Wizards of the Coast acquired its rights. Wizards opted to let Alderac Entertainment Group continue publishing second-edition material for the "Legend of the Five Rings Roleplaying Game" system.