Expansion suggestions
There have been very good suggestions so far. But I found that this game lacks in one very important thing: dynamics. I finished the game twice (as clan leader Nabu and Uesugi daimio’s vassal Ota) in less than 70 hours, which would be impossible in very successful games such as EU. I believe this was due to an accidental linearity of the game. To win the game quickly, one only has to exploit the overpowered Shinto faction and gain huge amounts of honor to prey on small clans. Start building one Shinto shrine in every new province and give it away to increased your Shinto influence and you’ll quickly be the leader of the faction and no longer have honor problems (if you go too far, just commit seppuku and start with you honorable heir). One plot to get rid of a big enemy clan and you won the game!
Thus I think both the religion and plot mechanisms should be improved to avoid their exploitation. Also, and as it was previously mentioned, the game is lacking in different events. These should be popping up different things that affect from small provinces to entire clans. Also, I feel most of events are one option only (as the other options are clearly out of question).
Religion
Religion should be a province attribute like in EU, but also a family attribute. Thus you could be a Shinto clan leader with Buddhist daimyo controlling Christian provinces. This would not only trigger a number of events, has it would influence relationship between characters, revolt risk and loyalty. You could convert provinces and vassals risking rebellions and defections, but gaining stability (less likely for same religion vassal to plot).
Also, Buddhist characters build Buddhist temples and so on, so a Shinto clan will have Buddhist temples being built in their territories. (The vassal has to build stuff for real, as I never had any vassal building anything beside villages and castles)
Plots
Plot are working very well, even though it is frustrating that I could use then only once in each game as I quickly became too strong. Thus, I’d suggest that the plot are easier to make (with characters deciding to join easier) but less effective, that is, the whole clan should be able to survive the plot, even though it would be weakened (All my plots completely obliterated the target). Also, the player should be target of more successful plots. I never had any plot succeeding against me, but I think having to constantly keep an eye on the vassals and dealing with defecting daimios would make the game much more dynamic. One could say that the samurai loyalty would prevent this much treachery and instability, but we must remember every one wanted to be shogun.
Diplomacy
I think diplomacy also fails in this game. The relationships result from a sum of factors and are too easy to control. Again, unlike EU, the relationships in Sengoku are basically dictated by what one did recently. Thus I don’t need to care for the relationships during the game, as giving them a gift now would be the same as giving them a gift later. What I suggest is that the relationships change over time like what happens in EU, that is the modifier is not +X relationship, but +X per months for Y months. Obviously gifts would have a small immediate effect but a longer effect. For example, sending a gift would give +5 relationships +1 per month per 6 months. There would be an annual decrease from “losing touch” with the character. Thus if I give a gift I’d increase the relationship +11 but I’d -5 as soon as the “recent gift” effect is gone, and -0.5 each month while no diplomacy action is made.
The vassal constantly asking for provinces is boring and forces the player to lose vassal relationship. I think the vassals should be smarter and just ask for province compensation instead of the next province, as well as asking for attached provinces to their own (no one likes to have a dispersed territory) in order to cluster their territories in different kuris, such as asking for Kai provinces and Ise provinces.
Some diplomatic options for the emperor would be interesting (something like the Curia or the HRE in EU). Even though he didn’t have power, he was still an important symbolic figure. In this case, being Shogun would not end the game, but give the player a bonus from the imperial house. Historically, even after being elected shogun, the whole Japan had to be united by force.
It is too difficult to break free as a daimio’s vassal. So, changing clans, plotting to usurp the daimios with his other vassals and being adopted into the clan famility would make it more interesting. Also, the daimio should offer provinces to his vassals and when they have a certain power they can ask to serve the clan directly (like a form clan option to break free from the clan, but this way to break free from the daimio and serve the clan leader). These smaller plots would also make it more dynamic for the player, as his own vassals might be forced to step down by their vassals. Obviously, this would only work if the player is forced to give away daimio titles. Thus the vassals could become very angry a plot very often if the player is collecting titles and not giving them away.
Also, as a vassal, one could ask for specific provinces to conqueror or to be given, instead of waiting for a random event.
Joining, forming and leaving clans should actually work and be more fluid. If a samurai is friends with an opposite clan leader, if would still be loyalty to desert a clan and join his friend’s clan. Loyalty would be to each character and not to a faction, thus making power shifts more dynamic and unexpected.
Also, by having too many vassal, it would be more difficult to be "friends" with all of them, thus having more vassals would indirectly result in more instability, thus a more difficult late game
War
In war, it would be interesting to discuss with the vassal were to attack. The vassal could agree or not with the suggestion, but it would tell what he’s plan is. This would to avoid all vassals going in the same direction. Vassals would focus on difference kuri in order to get a new daimio title (in agreement with their behavior suggested for diplomacy). I suggest that a province conquered goes to the clan leader and not to the vassal, and then the clan leader decides who gets which provinces. The vassals will have their favorite provinces and thus not giving it to then would affect relationship with the clan leader as well as making them jealous of the recipient of the title (possibly leading to daimios fighting each other, independently of the clan leader). War exhaustion is a very good idea in order to keep the big clans from just going on and on and on, taking everything. I also think that troops should not be allowed to march into other clan territory without permission or there should be a risk of war being declared by the owner of the province , a army moving in one’s territory could be seen as an act of aggression or possible treachery(for example, one could overlook such violation if in a difficult war to focus in immediate danger, but take it very serious if at peace).
Even though it is clear why alliances were not included in the game, one could question if loyalty to a friend clan leader would ensure a peaceful and collaborative time between clans. In this way, I’d suggest some variable to count for “loyalty” between each character pair, and thus this would allow “friendship” between different characters. This would also contribute to small clans surviving longer, as they will be protected by each other, or under bigger clan’s influence. (It is important that smaller clans don’t just disappear and that they have a chance, as smaller country do in EU)
Honor
Honor should be gained and lost trough warfare and diplomacy. The Shinto faction honor boost is too big and should be decreased. Honor should be lost by discovered ninjas and should be easier to get in small amount instead of difficult to get, but coming in large amounts.
Army
The expansion of the unit types into ashigaru infantry, samurai infantry, samurai archer, samurai cavalry, warrior monks and ashigaru arquebusiers would be an interesting addition to the game mechanistic as well as the option of choosing different army commanders with different war attributes such as movement (how quickly he moves he’s units in the field), tactics (how efficiently he orders he’s units in the field), strategy (how good he is in collecting Intel on enemy units, terrain conditions and so on, and using it for he’s advantage advantages), moral (how inspiring he is on he’s troops)... The samurai also run away, so they shouldn’t be completely annihilated every lost battle...
Levies would be make up of weak ashigaru infantry, while retinues would be stronger samurai armies, making retinues more importasnt in the game than they are (the retinue and levy representation also seems to be mixed up, as "ashigaru carry spears" and "samurai carry swords"!)
Arquebusiers don’t seem to be as good and influente as I hoped...
Rebels
Rebels should be improved, namely, by making them more aggressive. It is important to notice that, by using the proposed units, rebels would consist mainly of huge numbers of weak ashigaru infantry (and arquebusiers) and supported by smaller numbers of well trained warrior monks and, occasionally a ronin samurai army trying to get some land by supporting the people. Making rebels more aggressive and actually having them move and expand around the map wouldn't be as troublesome as it appears as they are mainly composed of huge amounts of weak units, while the samurai armies of the clans are much better trained. This would keep those white Ikko-Ikki unconquerable blobs from showing up in the map and also keep the rebels a real moving nuisance.
Ninjas
It would make much sense that the ninja clans are harder to find, but that once they are found they can be hired into serving the daimio. As such, they would take a monthly fee, which is somewhat dependent on their attributes. The ninjas would serve the samurai until they found a better employer or they’re leader's relationship is too bad with the clan’s leader. This would be affected by ninja clan’s rivalry, so hiring a lot of ninja clan’s could actually turn them against you as they don’t like each other.
Trade
Trade would be something interesting to see in the game and could add some micromanagement fun. As such differente provinces would have different "resources" and the choice of which kuni to control and conquer would be less random and more interesting, making the game map less homogenous. Also, the building mechanics see fine, but the clan should pay for the village and castle improvements to make it more difficult to build everything. Price would be compensated with the extra trade income that each province would have. Traders could be added to the court in order to overview the trading and commerce in the character’s provinces, as well as trading buiding could be added if the "Master of trade" also has 3 different options as the other "masters".
Territories
I don’t think the daimyos were much concerned with Korea or China during the Sengoku Jidai, so I don’t think adding these two regions would be historically significant. Also, the Samurai are not famous for their naval warfare, so I’m unsure how good it would be to add pirates and navies... even though a small role could be given to naval units.
AI
The AI should be able to do everything the played can do, from joining other clans to having internal problems and successful plots. If this does not happen, then the game would be unbalanced.
