Simplify the following text for a Grade 15 native English-speaking person.
Original: These stories typically involve `` frontier '' colony worlds ( colonies that have only recently been terraformed and\/or settled ) serving as stand-ins for the backdrop of lawlessness and economic expansion that were predominant in the American west .
Simplified: These stories are often on `` frontier '' colony worlds ( colonies that have only recently been terraformed and\/or settled ) serving as stand-ins for the backdrop of lawlessness and economic expansion that were predominant in the American west .