In Supreme Ruler 2020 there are 16 terrain types.
All land types except 'Mountain' may be flat-ground or high-ground; Mountain terrain is always high ground.
| Terrain | Land Units? | Naval Units? | Notes |
|---|---|---|---|
| Plains | Yes | No | Easily traversable by wheeled and tracked units. |
| Rough | Yes | No | Slight penalty for wheeled units. |
| Light Forest | Yes | No | Penalty for Tracked, greater penalty for wheeled. |
| Dense Forest | Yes | No | Penalty for Tracked, greater penalty for wheeled. |
| Jungle | Yes | No | Penalty for Tracked, greater penalty for wheeled. |
| Swamp | Yes | No | Penalties for both Tracked & wheeled. |
| Semi-Desert | Yes | No | Penalty for wheeled units. |
| Rough Desert | Yes | No | Penalty for Tracked, very high penalty for wheeled. |
| Mountain | Yes | No | High penalty for Tracked, very high penalty for wheeled. |
| Tundra | Yes | No | Penalty for Tracked, very high penalty for wheeled. |
| Coast | Yes | No | Penalty for Tracked, very high penalty for wheeled. |
| River - Narrow | No | No | No Naval Units; Amphibious land units only |
| River - Wide | No | Yes | Naval Units and Amphibious land units only |
| Lake | No | Yes | Naval Units and Amphibious land units only |
| Ocean | No | Yes | Naval Units only |
| Impassible | No | No | Impassible to all but air units |