Complex sentence: In Open range, all buildings are unlocked from the start, while in Disaster Challenge, where disasters, like tornados, earthquakes, fires and bandit attacks take place, you must unlock new buildings using the experience and resources you recieve as the difficulty increases.
Split into simpler sentences: In Open Range, all buildings are unlocked from the start, while in Disaster Challenge, disasters like tornadoes, earthquakes, fires and bandit attacks take place. You must unlock new buildings using the experience and resources you receive as the difficulty increases.