Limes denarius (Lim-ace) or coins of the borders, were bonze versions of silver denarii struck from official dies. They may be another example of coins of necessity issued because of a shortage of silver in the border regions. It has also been suggested that they may also be officially sanctioned issues for use in regions where political unrest made it hazardous to ship large amounts of silver. Others have suggested that they were used to pay barbarians on the fringes of the empire for local work.
The most likely reason for their issue is based upon history repeats because human nature and its decision process will lead to the same conclusion no matter what the century. Therefore, it also remains possible that these were military scripts paid to soldiers on the front lines just as they did during World Wars I and II to pay locals. They would have reduced the need for vast amounts of precious metals on the front line or actually having US paper dollars that might have been sized by the enemy in a battle.
These Roman bronze issues of denarii could have served troops on the front and been redeemable for good coinage when they returned to the stable regions. Whatever the reason, many of these coins exist. They have been often viewed as possibly “coins of necessity” issued during periods of a lack of silver. Some examples may still bear traces of a very thin silver wash. It seems that they were probably military script since the very same practice took place in modern wars.
A “Limes Denarius” were struck from official dies. Thus, these AE denarii official issues use the same dies as those intended for the silver denarii. However, there are also some that appear to be cast from typical clay forgers’ dies and sometimes may have been cast in molds. It is possible that the opponents forged this military script version of the denarii.
There are no written accounts of this practice within the official monetary system. However, if troops are paid with real money and they lose a battle, the opponent will then seize whatever money they had and use it to further fund their operations. If the soldiers only have a military script, then there is no financial benefit to the opponent if they should defeat your troops.