The Natural Expansion is the expansion closest to a player's starting position. While most commonly separated by a ramp and placed directly outside the starting base of a player with a choke protecting the entrance, maps have varied with the design of the Natural Expansion.
- Scrap Station features a Natural Expansion which is down an abnormally-large ramp, and includes a secondary Destructible Rocks entrance along with a high-ground island.
- Xel'Naga Caverns has Natural Expansions which have three open entrances (one protected by Sight Blockers) with a fourth defended by Destructible Rocks, rather than a choke.
- Crevasse includes Natural Expansions which are accessible only through the main base or by air, allowing for easy defense-free expansion, at the cost of increased air threat.
- Desert Oasis features a Natural Expansion which is considerably far from the main base and includes a Destructible Rocks backdoor, both of which increases the difficulty of defending and expanding to the location.
Many build orders, such as the Forge Fast Expand, Hatchery First or 1 Rax Fast Expand, are specifically tailored to taking the natural expansion early. This is a calculated risk, designed to get the economic boost of a second base quickly to transition into the mid game with an economy focused build.