Atlantian

The Atlantians consist of (mutated primates) Atlanteans, Humanoids and some small species from other planets. The (mutated) primates become smarter and cognitive Atlantean and quickly evolve (quickly is ... over thousends of years), some offspring isn't genetically modified and therefore less capable. They tend to investigate more and some leave the dome after finding small unsealed sections or working their way out. Something Aivitu didn't consider important at all.

Exhaustion Table (normal)
6 exertion -6 to rolls, CON roll DC 5

7 exertion -6 to rolls, CON roll DC 10

8 exertion -6 to rolls, CON roll DC 15

9 exertion -6 to rolls, CON roll DC 20

10 exertion -6 to rolls, CON roll DC 25

More exiting:

Exhaustion Table (normal)
6 exertion -6 to rolls, CON roll DC 5
7 exertion -6 to rolls, CON roll DC 10
8 exertion -6 to rolls, CON roll DC 15
9 exertion -6 to rolls, CON roll DC 20
10 exertion -6 to rolls, CON roll DC 25

and finally:

exertion	roll	DC	Note
6	-6	5	a
7	-7	10	b
8	-8	15	c
9	-9	20	d
10	-10	25	e

and the table can be changed for look and feel with CSS