It is often said that 4x games suffer from the “snowball effect,” whereby by the mid-to-late game a faction has grown so much as to be unstoppable, and excessive micromanagement, again particularly in the late game, when empires have grown large and complex. What follows is a design to solve these problems, resulting in the late game being restored as a dramatic climax instead of a tedious slog. The setting is human history, like the Civilization series or Humankind, because I like the variety in a land-naval-sea environment compared to a mostly naval one, which tends to be the case with 4x games set in space.
The core concept is a new metric called Imperium, hence the title. Imperium is a measure of how much an empire is able to do, and everything players do costs Imperium, including ordinary peacetime functions such as revenue collection. It is also the currency by which civic policies are unlocked. Some amount is provided at the start. Aside from that, it is earned by winning wars, and by certain civics and religious tenets, which provide an increase in the baseline amount of Imperium. When Imperium is low enough and unhappiness is high enough, rebellions will break out and there is a good chance the empire will fragment. If this happens, the breakaway(s) become factions in their own right. Imperium costs increase the larger the empire is, both in terms of land area and population.
This is based on historical rise-and-fall dynamism. The longest lasting real-life faction I can think of is Venice, a city-state, which lasted a thousand years. No large empire has ever lasted for more than 250 years without fragmentation of some kind (although cultures can last longer). Now, of course, players in 4x games aren’t historical people but immortal demigods, giving their domains an element of stability not historically present, and it is certainly possible for a single empire to last throughout the game. Nevertheless, incorporating this dynamic in a mild form gives an advantage to the “tall” playstyle and gives “wide” factions an element of perishability which makes it more difficult for them to snowball. On the other hand, balance is also present, because although it would be possible to keep one’s faction so small that it could easily handle the periodic waves of internal strife, it would then be pretty vulnerable to invasion in most situations and would probably lack the capacity to be competitive in terms of winning the game.
An important supplemental mechanic is supply lines for armed forces. To prevent this from becoming tedious, they are calculated entirely by the computer, based on the productivity of the country or countries units belong to, combined with the transportation improvements or lack thereof in a given area. All the player has to do to determine the supply situation is go to Military Map Mode and the supply limit will appear as a line on the map. The penalty for having outrun or being cut off from one’s supply lines is being unable to heal except by pillaging. Players can pillage/destroy their own improvements in a scorched earth policy.
Combined, these two mechanisms mean that an empire could control 50% or more of the map and still realistically be toppled through military overstretch and rebellion. That said, it is still possible to be super-expansionist. In the short run, this is actually potentially easier. A faction could, for example, defeat a major rebellion and earn a lot of Imperium, which is then used to unlock a large number of civics, allowing for great increases in revenue, the proportion of the population subject to conscription, and so forth. This is consistent with real life, in that historically, great change often took place in a short amount of time, for example, the Neo-Assyrian revolution of Tiglath-Pileser III or the Meiji Restoration, in contrast to most 4x games in which change is incremental.
For the turn-by-turn flow of the game, the general rule is that unlike in most 4xs, decisions are typically made at the national level instead of regionally or city-by-city. Each turn, the player cycles through and make choices in a few key areas, Military, Fiscal, Construction, and Diplomatic. In other words, under Construction, there would be a “Construct Public School Network” decision instead of a Public School building which has to be selected in the build queue for every city individually. The main concern for players at the regional level will be applying civics to increase yields throughout the empire and reduce the amount of Imperium required to maintain it. Since this means there might be too few instead of too many decisions to make, there is also an “events and decisions” system which presents players each turn with more everyday choices relating to maintenance and upgrades for current buildings and structures.
There are four main yields, Imperium, Popularity, Productivity, and Currency, as well as natural resources such as Food, Coal, Oil, etc., which act as inputs to the latter three. Imperium has already been described, while Productivity is a combination of what other 4x games call Production and Science. Popularity and Currency are what they sound like.
The map does not have a grid, as the game, like Europa Universalis IV, is area-based, not square-or-hex based. However, unlike in EUIV, the areas are not predetermined but rather develop organically as the events of the game unfold, as players subdivide their countries in more complex ways. Within them, cities, for the most part, grow up gradually according to population growth, access to transportation and natural resources, and so forth, as they historically did, without the player directly ordering the process, although it is also possible to construct a city by fiat if the player feels it is worth the expense. Also, there is no minimum distance between cities, which can be so close to each other that they eventually merge.
With the factions, I personally dislike the practice of rerolling for better starts, so all starts are the same; the player is the paramount chief of a small sedentary society, which has ceased to be mobile before the game began. The information about the outside world is limited and visible access to natural resources at the start is always roughly similar to any other start. Of course, since snowballing is much less prevalent, starting advantages are correspondingly less important. There are no minor factions or barbarians as separate categories and all are trying to win, although in the normal course of events one can expect many to end up so small that they act like city-states or barbarians. Since the start represents the dawn of sedentary history, no one starts out with unique units or abilities. These are awarded to individual factions as the game progresses, based on actions they tend to engage in repeatedly.
For the technology tree, I find strategies like rushing this tech to speed up research on another one due to be completed in 1500 years’ time artificial and gamey. People don’t have the ability at any given time to see beyond the leading edge, and how long research takes in any given area is always somewhat random. Also, most research isn’t concentrated on one area by fiat of the ruler. Therefore, the tech tree is somewhat randomized each game, although of course not to the extent of having progression occur in a bizarre order, and the player doesn’t see it beyond those immediately available to research. How long research on a given tech takes is also semi-randomized, i.e. the player would see “6-8 turns” instead of a preset number. All techs pertaining to activities the country engages in are automatically researched simultaneously (the exception would be, for example, a completely landlocked country, which wouldn’t automatically research techs pertaining to oceangoing ships), with the default position being science output being split equally between them. However, the player does have the option of giving research grants to speed up progress on one or more techs. There are no eras, which are, in my opinion, somewhat arbitrary labels given by people after-the-fact. Instead, the impression of eras will arise naturally from the progression of events in the game itself.
For the military aspect of the game, units cost population, and the player has the option of leaving units in training for longer than necessary for higher quality, up to a limit defined by the faction’s military education level. This means that, as in real life, there will tend to be a higher-quality standing military in peacetime combined with a larger number of lower-quality units created after the war starts. Exceptionally experienced elite units gradually lose their promotions in peacetime until they are level with the best unit the civ is capable of training, representing the retirement of battle-hardened personnel. There is no unit stacking, but because there aren’t hexes or squares, units, while not exactly to-scale, are far closer to real life scale than in most 4x games.
Movement is variable, with units having a basic and maximum movement ability, the basic being how far it can move without suffering a combat penalty, which grows progressively more severe towards maximum movement. This means players have the option of pushing an advance hard if they feel speed is of the essence, but at the risk of being exposed to easy defeat. Combat is resolved simultaneously after all players have completed their turns (the order in which the end turn button was clicked is irrelevant), meaning that if two sides are moving towards each other they would clash in the middle with neither reaching their intended destinations before the fighting starts.
I picture the victory conditions as being similar to those in the Civilization series.