REFLEXIONS ON SUPPLY
1) Fighting the blurriness of supply in vanilla RoP
In vanilla Risa of Prussia, all troops come with an "internal supply storage" of 2 and consume one supply point per turn.This means that in good weather a force can operate for 3 turns totally independently of supply: in the first turn it fills up its store and is moving away from its source of supply (internal supply stocks 2/2), in the second turn it consumes one point (supply stocks 1/2), in the third turn it consumes the second point (supply stocks 0/0), and only in the fourth turn will it count as being out of supply and suffer negative effects. Not before the fourth turn – that is after incredible 6 weeks of marching! – will the first negative consequences set in.
Of course a certain level of abstraction is neccessary in a game, especially when it comes to things as logistics - an aspect which is usually not embraced wholeheartedly by most players, even more so when they have to worry about 4 armies every turn! Yet the role of supply is highly underestimated and I dare say it was by far less forgiving than the games' abstraction. AGEOD is well aware of that, quoting Pocus from
here, but intentionally lays its focus somewhere else:
Supply should be something that should be easy on players in 95% of the time, and only be a problem in specific situations... For example a given supply point will de facto travels much faster than what a supply wagon can do in 15 days. I guess, from the remarks and questions, that you would prefer something much more stringent and hard, realistic. My answers will indicate on the contrary that the system, even if the restrictions are logical, is rather 'lax'... That or you screw all non veteran players plus the AI, all the time.
Silesia Inrupta strives to make supply more "realistic/hard" and thereby aims to give a more accurate picture of 18th century warfare which not only consisted of big battles, but far more commonly of small actions which were waged over positions and forage. Without a "hard" supply-mechanism, small war and detachment warfare simply doesn't work and serves no purpose at all. So, what is even more important than considerations of realism are the consequences on gameplay. If your opponent doesn't have to care for supply for 6 weeks, your chances to threaten his position by means of cutting him off and manoevering are very slim. You are neither able to threaten (in a timely manner) him by positioning light troops in his rear (and moreover, this was quite suicidal for light troops), nor by destroying all depots and local supplies on your retreat. Apart from that, due to long turn-intervalls, outmanoevering was by itself extremely difficult and based on a lot of luck.
Apart from supply being so forgiving that it almost becomes irrelevant (as it is simply checked so rarely), long turn intervalls tend to make supply even less of a matter. Since units in vanilla RoP depend entirely on their internal storage (+ supply wagons) and the automatic (centralized/de-localized) supply-system, they operate independently of the local supply situation. Long turn-intervalls contribute to this even further by enabling forces to "hop over" (by means of their movement allowance in 14 days) regions that would otherwise pose supply problems.
Therefore, supply in Silesia Inrupta works on turn-to-turn basis (internal supply storage of 1, not 2) and turn-intervalls are set to be shorter (less "hopping over" regions). This should open up much more chances for and reward manoevre and logistical-operational considerations. Supply will be checked every single turn and you cannot hop over regions (except for fast/light troops). Every turn and every region counts, so to speak - at least for regular units.
2) Sources of supply
In general, supply in RoP is handled in a very centralized manner. It is all about structures that are few and at the same time of immense importance. Structures produce supply en masse and forward it to the structures closest to the front where it is distributed to your armies. In fact it was very easy to keep supplied if only you brought enough supply wagons. Since they had such a huge storage, you hardly ever needed to rotate them back and forth between a supply-source and your army. Thus you hardly ever had to offer your opponent chances to "see" your supply line and act against it. Most of the time, your supply wagons were safe and secure in your main army stack.
Of course this needs to be changed in Silesia Inrupta: Players depend on a mixture of two supply sources. Note that to maintain a large concentration of force, you should be forced to make perfect use both sources. And also your enemy can try to threaten any of these sources:
a) Supply by depots (centralized supply)
At the start of the scenarios, you will have one or two depots that store enormous quantities of supply – as it was usually the case historically. This supply will only get forwarded to other depots, not to cities. As usual, this supply can be transported via supply wagons and – by far more effective - via ships on rivers. However if the distance between the depot and the army is too big, supply will slowly spoil (represented by the fact that supply wagons also consume supply every turn - not entirely sure yet if that works).
So the big changes compared to the vanilla game are: 1) Only depots, not forts/cities/harbours send and draw supply (but they can still give supply to adjacent regions). 2) Depots, harbours and forts no longer "produce" supply. You have to use what's there at the start of the scenario and/or buy special supply assets.
Another very important aspect concerning supply by depots is the storage of supply wagons. Even though it means a lot of micro-management, supply wagons in Silesia Inrupta have but a comparatively small storage capacity. There are two reasons for this: 1) A small supply storage forces you to operate close to depots due to supply-spoilage. 2) A small supply storage means that you need to rotate the supply wagons a lot. They have to go back and forth between army and depot, which makes supply-lines real and vulnerable to the opponent in the first place. If you have but one supply-train to sent in two months, then the opponent gets but one pathetic chance. Supply lines need to be constantly "real" and "accessible" and the effect of them being blocked should set in fast. Being cut off from supplies for 6 days was a very big problem historically speaking.
In general, this means that supply will be much more visible (and "attack-able") in the modded version of the game. You see where the depots are, you see where the supply wagons are (and they can't be "hidden in/protected by" the large main stacks all the time), and you know that there is some supply in the country-sides (see next point).
b) Supply by cities=regions (local supply)
The only agents that actually "produce" supply in Silesia Inrupta are cities. However these are just called cities in game terms. I rather imagine them to represent the "region/countryside". As a consequence, Silesia Inrupta features a (lvl 1 or 2) city in almost every region to represent the local/countryside supply-situation. Eevery region produces small amounts of supply, which also accumulates over time. In the same vein, cities that had a high level in vanilla Rise of Prussia have been reduced to a lower level in Silesia Inrupta, simply because it is not "cities" that produce fodder and flour, but the countryside.
In ageod's games, armies can draw supply from adjacent regions. This is also how local supply works in Silesia Inrupta: A larger army will try to drain supply from adjacent regions, and it will often literally depend on this supply for its maintainance. In order to use local supply, however, you need to control a region/city. You can already guess where this is leading us: Players have to try to keep a certain sphere of influence (all adjacent regions) around their armies under their control if they want to maintain their men. As there is no marching to the sound of guns (corps' and armies' positions were blurred as they could become active everywhere) and as there is a special way that light troops work in this mod, expect fierce detachment- and small-war over regions and their supply, offside the main armies. Grenadier-companies, hussars, dragoons and Grenzers are your fist choice for these tasks. Moreover, the dependence on adjacent regions also means that the number of adjacent regions is an important consideration, as it is proportional to the amount of supply that a certain position offers.
At the same time, it is also clear that local supply will make it easier for small detachments to operate, as they don't need to drag a supply-train with them. I don't think that this is a big problem. Your supply-wagons (rotating between depot and army) and your depots should be escorted/garrisoned anyway. Moreover, since there are cities in every region, it's pretty easy to defend a region with a small garrison. And in the vicinities of your main army you should have enough detachments and light troops to defend adjacent regions. So deep raids should not be too much of a problem, they're part of the game. Also consider that any deep-raiders are not where they're probably needed more urgently: in the small war for forage around the main armies.
Last but not least I also have to mention that the effects of being out of supply have been toned down quite a bit to compensate the fact that it is much easier to run into supply problems in this mod and because the turn-intervalls are shorter. E.g. there are no movement penalties for being out of supply (why should there be some in the first place?), the battle-malus has been reduced, and the desertion rate lowered (the AI is immune to desertion due to lack of supply).