Complex sentence: Once they acquired certain key dungeon items new areas of the overworld become available; for example, once a player has the Magic Hammer he or she can knock previously unpassable pegs into the ground, allowing access to the area it blocked.
Split into simpler sentences: Once they acquired certain key dungeon items, new areas of the overworld become available. For example, once a player has the Magic Hammer, he or she can knock previously unpassable pegs into the ground, allowing access to the area it blocked.