- -60% attritional losses when besieging
- -1 enemy siege hold-out time (double for city-ports)
- +15% missile damage for all siege units
Roman siege equipment was, with the exception of some specialist pieces, always constructed on campaign. This meant that those who were expected to use it needed a good level of engineering knowledge. As well as a working knowledge of the workings of their machinery, the crew were expected to carefully manage the projectiles, making sure that they were the correct weight and could reach the required range.