Vegetius was full of odd strategems to mislead the enemy or demoralize the enemy troops. Once the enemy cracked, they were not to be surrounded, but left an easy escape route. The reason for this is that trapped soldiers would fight to the death, but when left a possible escape route, they were exposed to the cavalry waiting on the flanks.
"Roman Army Tactics." The Roman Empire. Web. 23 Mar. 2010.
http://www.roman-empire.net/army/tactics.html.
Cracked Surface 2. Digital image. Wikimedia Commons. Web. 16 Apr. 2010.
http://upload.wikimedia.org/wikipedia/commons/a/ab/Cracked_Surface2.jpg.
