Level 23

Total Experience Required 68,021

Level 100 progress: 1%

This is roughly the same as:

Killing 114 people in Warzone, or...
Killing 116 people in Execution, or...
Killing 97 people in Wingman, or...
Scoring 24,294 points in Guardian, or...
Scoring 73,936 points in Annex, or...
Scoring 44,751 points in Submission.

Horde (TU4)

Completing 171 waves on Casual, or...
Completing 114 waves on Normal, or...
Completing 86 waves on Hardcore, or...
Completing 69 waves on Insane.

Or a combination of the above. Have fun!