Rocks are on nearly every single planet and can be used in any manner you really see fit, you can make a debris field, or a boulder field, or a natural field faded by time.
In the Antares rule book, these can be used in any formation but most likely will be recognised as rocky ground which has this profile:
Line of Sight
Light Terrain
Cover
+1 Resistance
Difficult
Yes
This set comes with 1 large, 1 medium and 6 small rocks plus the MDF terrain area plates.
Models supplied unassembled and unpainted
