In DUNE you will become the leader of one of six great factions. Each wishes to control the most valuable resource in the universe - melange, the mysterious spice only found at great cost on the planet DUNE.
As Duke Leto Atreides says “All fades before melange. A handful of spice will buy a home on Tupile. It cannot be manufactured, it must be mined on Arrakis. It is unique and it has true geriatric properties.”
And without melange space travel would be impossible. Only by ingesting the addictive drug can the Guild Steersman continue to experience visions of the future, enabling them to plot a safe path through hyperspace.