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Dev Diary #104: 19th of October 2020

Dev Diary #104: 19th of October 2020

Hello and welcome to another development diary for Imperator: Rome.
Today I will be talking to you about some of the changes that are coming in the Marius update. It is still early days, so take any and all numbers and screenshots as what they are, work in progress :)

Combat Width

In Imperator: Rome Combat Width is what determines the size of a battlefield. Units designated as primary rank are deployed in the center, with the units designated as second rank taking their place once they retreat from the battlefield. Units designated as flankers are deployed on the sides.
If unopposed to their direct front, units will target enemies diagonally, as far away as their maneuver rating will allow. This means your flankers can start attacking the center of the enemy line, if they can first defeat their counterparts in the enemy flank. It also means you will have little use of your flankers until late in a battle if the enemy line is completely filled.

The unit interface is changing a bit in Marius, here is a partial peek at the Work-in-Progress version of it :)

In the Marius update combat width is no longer the same on every battlefield. Instead it is now dependent on what terrain you are fighting on, and this can vary quite a bit, from extreme cases such as mountainous terrain where the battlefield is only 16 positions wide, to sea battles in the open where the width is now 50.

This allows us to better represent a dramatic variation of combat scenarios, and potentially opens up opportunities for ambushes, pitched warfare, and more. Choosing the place you give battle becomes as important as which subunits are present.

Additionally there will be some locations where the width is further modified, for example mountain passes, like the famous “Gates” where many historical battles took place. Such locations are now also marked with a 2D icon on the map itself. Such passes have been added to a number of locations all around the world.


What this means is that it becomes less viable to trust that one army composition is as useful for all types of campaigns. In largely forested or hilly areas your ability to flank will be much more limited.
At sea, on the other hand, this increases the danger of leaving your heavier ships unattended even further. The new system allows the potential number of enemy ships that can target a single isolated big vessel to be much higher.


In the release version of the game, when you have broken through a fortified area you currently have to spread out your troops to take control over the unfortified parts of all the provinces you pass through. This is a process that can be both attention intensive and not particularly rewarding or realistic.
For the Marius update we have been looking at ways to alleviate this, removing reasons to break your armies up into many small pieces and rewarding concentration of power a bit more. Some of these changes will be described below.

In the new update occupation of all territories in a province will begin to progress as soon as you control *all* forts in that province. This means that when you are done taking control of the military installations of a province your armies can move on, and not split up to occupy all the territories in turn.

In provinces that do not have any forts, it will be enough to occupy the province capital to trigger this behaviour. Occupying the local capitals was already a good idea since it gives your armies access to the Provincial food storage, but this change further increases the importance of going after these important locations.

This has the knock-on effect of reducing the need for carpet-sieging behaviour, and makes large-scale warfare significantly less tedious.

Province Fort Limit

Another change, partly because of the new importance of forts, and partly because of how easy it has been to tie down invaders by building a great number of small forts, is the Provincial Fort Limit.
This limit represents the degree to which the provincial infrastructure can support great fortifications and can be increased using a provincial investment.
The starting limit for any province will be 5 and each new fort in a territory will make use of 3 Fort Infrastructure levels. Additional levels to existing forts only contribute 1 Fort Infrastructure level to the fort limit, encouraging building forts in important and influential places rather than in every territory.
The Fort Limit is not a hard limitation, you can still build more fort levels than your province infrastructure can support, but fort levels beyond the limit will sharply increase the maintenance you pay for them. There may well be additional sources of this limit to account for historically well-defended locations.

Engineer Cohorts

Fort warfare will also be affected by the introduction of a new Engineer Unit type. This unit represents troops specialized in sieges and the construction of military facilities, siege towers, roads, temporary bridges, etc. If present with an army laying siege to a fort, engineers will add +1 to every siege roll, divided by the fort level +1.
Engineers are also able to negate the crossing penalties that armies get for attacking across rivers or straits, as long as they are present in high enough numbers (1 cohort for every 10 units fighting on your side in a battle). For this reason an icon indication has also been added to show whether you will get a crossing penalty or not from a movement order.
Lastly Engineers are proficient in road building and will greatly reduce the cost to build new roads if they are present in an army ordered to construct roads.

The new unit type has an unusually high cost both to recruit and maintain, and is also restricted in some ways that we will expand on later diaries.

That was all for today when it comes changes related to warfare. Now it is time for a change coming to how you handle trade.

Provincial Trading

One other new feature coming to the Marius update is the ability to assign control over Trade to your Governors. This is done on a provincial level, meaning you can decide to have some provinces under the control of your governor while still manually handling others.
The governors will try to get profitable routes set up while also securing access to food for their territories, but will expect to have total control over what is theirs

Atlas Map Mode

My last point for today is to show the new Map Mode that we are adding together with the interface rework in Marius. It aims at showing information at a glance in a way that could be useful for After Action Report screenshots, or if you just want to admire your world in a way reminiscent of the historical atlases that most of us enjoy :)

That was all for this week! :) Next week we will be back with more about the new features of the Marius update.