Level 13

Total Experience Required 21,347

Level 100 progress: 0.31%

This is roughly the same as:

Killing 36 people in Warzone, or...
Killing 37 people in Execution, or...
Killing 31 people in Wingman, or...
Scoring 7,624 points in Guardian, or...
Scoring 23,204 points in Annex, or...
Scoring 14,045 points in Submission.

Horde (TU4)

Completing 54 waves on Casual, or...
Completing 36 waves on Normal, or...
Completing 27 waves on Hardcore, or...
Completing 22 waves on Insane.

Or a combination of the above. Have fun!