兵家诡道

This guide aims to ease the course of a ruler's conquest and expansion while providing detailed situational overview on most regions at the main start dates and explaining how to win all wars to all neophytes in this matter.实验（实验）

Although a meagre work compared to the original Art of War, several of its concepts will be applied in this guide to CKII, in order to give all players a decisive strategic edge over any AI and players in most given situations. In no case, however, are the concepts detailed here applicable anywhere, anytime. Your expertise will decide whether to apply or not the following strategies in a specific situation.

The Sinews of all War

A war can only be won by keeping in check the two dual aspects of Medieval statecraft: economy, and levies. Strong economy supplementing stronger armies is key to victorious campaigns.

Developing both of them in a well-balanced way will allow you to spend virtually all your game warring without ever feeling any attrition of your army or witnessing the crash of your economy. As such, a careful balance must be found between economic and levy size development.

The ruler skill in martiality is far more influent than the buildings, at least at the beginning, to raise levies. If you have enough revenue then to maintain all your levies, consider educating your heir or choosing any martial focus to expand cost-free your army. Developing buildings will become useful at peacetime when you'll have money to spend and reached demesne limit.

In the opposite case, when you get deficial with your levies raised, two choices are offered to you. Either stockpile money in order to be able to expand quickly, and then count on your newly acquired vassals to pay for your future campaigns, or be even more patient and build up economic buildings in your demesne. If you are near the Silk Road, just build up the Trade Posts, and eventually your money problems will vanish, unless China encounters internal trouble which disrupts the Silk Road ().

Your vassals will also have a slight role to play, as with sufficient Crown Authority they will both expand your levies cost-free, and give you enough taxes to supplement your own demesne army. However, a strong reliance on vassal troops is very negative; as the vassals that like you will give you more troops than the ones who hate you, any crushing defeat on the battlefield will have a tremendous political impact. Factions which already exist will gain a sudden surge of power, and may be powerful enough to declare war on you. As such, it is always preferable to develop your demesne and its troops than to create strong vassals.

Enemy & Ally

After each prolonged period of peace, or before unpausing, you will have to choose your archenemy, the enemy you'll try to weaken both diplomatically, economically, and to invade when the right time comes. Once finished with one, you'll have to choose another one, under the same criteria.

The perfect rival will have to meet most, if not all, of the following criteria:

• Be a lot weaker than you, and within immediate reach
• Be a heathen
• Be isolated diplomatically (cultural differences, or simply without alliances)
• Be of equal realm size than you, but with a slightly weaker state on a military point of view (lower army size, reliance on , or equal army but with a significant proportion of event troops)
• Have powerful and unhappy vassals
• Be within your de jure kingdom or empire

This enemy will suffer in priority all your efforts to expand from your tiny strip of land.

After choosing your enemy, focus your economical resources on fabricating claims, inviting claimants (see Expanding your realm for this part). When a Casus Belli is found, here comes war.

If you are not ready to attack by yourself a larger realm, consider making an alliance with prominent members of your religious group. The Holy Roman Emperor or the Caliph are the best examples. With their support and very large armies, losing the war will be very hard. Be mindful though that an ally making war by himself is useless for yours, as his troops will be busy elsewhere.

With Jade Dragon, the tributary system also allows for easy alliance forming. By declaring tributary wars on smaller, peripheric states, you will be able to constitute a large zone of influence faster than by conquering them one by one, allowing you to take on your enemy with greater peace of mind.

Keep in mind though that relying on allies to win a war can jeopardise your chances to win it. In battle, some of their flank commanders may be chosen to lead a flank of your combined armies, even if you have a far more competent commander leading your troops on this flank. When besieging, the attacking commander will be the one of highest rank. Your , if he is a courtier will be likely to be replaced by any landed commander your allies may bring along with their forces, regardless of how incompetent he may be.

A Timely War

“Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win” - Sun Tzu, The Art of War

Declaring war on an enemy's country is no easy decision. You will have to consider a number of factors, and the mightier your enemy, the more important each of the details will become. It is only after you are certain of your ability to win the war with minimal time and losses that you can declare war with the appropriate preparation.

Have an efficient chain of command

The position of commander is most decisive when a battle comes. As such, each of your posts should be occupied by the best men you'll be able to find and to get to your court, by inviting them or forcing matrilineal marriage. Usually, this only works with people from your religious group, although buying favors can sometimes bypass their initial reluctance.

Once the best commanders of your religion are in your court, consider balancing their talents, as this will provide you more strategic tools to win your war. For the least, try to have:

• 1
• 2 Flank leaders
• 1 Center Leader
• 1

Some traits can also be especially useful, such as:

• or which gives +20% Defense,
• which gives + 20% Morale resistance
• which adds 20% Siege speed
• which gives 10% movement speed
• , which give more narrow flank chance, useful when facing larger and lower-quality armies
• which deals 10% more morale damage
• and which allow for more damage in the Pursuit phase.

All of them can be acquired, by torturing prisoners for instance, or by choosing the War, Governance or Hunt focuses. Some events can also grant randomly these traits to your character.

Their martial skill is secondary, given they have the right traits (hover the mouse over the shield and swords symbol on their profile to view their influence). A commander with average martial skill but great traits is preferable to another with very high martial skill but few useful traits.

With proper commanders, every battle can be won.

Be prepared financially

If you are not self-sufficient with your levies raised, or if you plan on hiring mercenaries, make sure that you have enough money in your chests to provide for a lengthy war.

Risks of bankrupting in the middle of a war are numerous, among which:

• Your mercenaries may turn on against you, by joining your enemy or declaring an invasion of your realm
• Being in debt gives the very negative -25% morale buff to your army, significantly depleting your chances of winning any battles
• Negative modifiers may spawn up in your demesne, hampering tax, levy reinforcement among others
• Other nations will see you as weak prey. This may lead to an uncontrollable multiplication of war declarations, tearing apart your hard-earned realm.

To avoid these, you can start stockpiling money, but also choose the ambition "Build a War Chest" and extort money to your subjects, borrow money from the Assassins and Jewish merchants, or more sadistically, invite rich but heirless people who are disposed to join your court and kill them off, in order to inherit their wealth.

Choose the right war goals

With a set of Casus Bellis at your disposal, only the one that will bring you the most long-term benefits, and target easily reachable provinces is to elect.

For instance, a Holy War targeting a faraway but large duchy (such as Tunis) won't always be preferable to a smaller one if you won't be able to defend it on the long term, or if it will bring you a Jihad once in every 30 years.

While under your demesne limit, prioritise wars that will bring you, and not a vassal, new land to dominate. Once you reach this limit, three aspects are to be considered.

• If you want a culturally homogeneous realm, favor claims from your vassals or from a same-cultured courtier. Holy wars and de jure claims are also a good option.
• If you only desire fast expansion, pick the claims that will bring to your realm the most neighboring lands, or higher tier title.
• Finally, respect as much as possible de jure kingdoms and empires, as holding them will bring you greater tax and levies from your vassals, and also negate the risk of national revolts.

Attacking weakened realms

Special attention must be paid to weakened realms, as their conquest may not be as easy as it looks. Firstly, check the army limit, and not the current army size, of your target. Troop reinforcement rates can be surprising, and you'd end up fighting far too large armies over time. Some realms also have vassalised mercenaries (such as Egypt from 1066) or Holy Orders (like Castille). Failing to take into account these enormous and elite reinforcements could seriously compromise your chances of winning the war.

Second, make sure that if you attack rebels, neither their liege nor they have more than 25% warscore, as this would lead the rebels to surrender or to offer white peace to their liege before your war ends. A good way to avoid it is to occupy their territory as soon as possible, as a war between a rebellious faction and its liege may only end when the rebels do not own any properties that are occupied by powers other than their liege.

Last, but not least, check their Pacts, or their same-religion neighbors if going on a holy war. You never know who will enter the war on their side, and the AI is very good at making unforeseen alliances when in danger.

Troop Deployment

Once war has been declared comes the moment to levy your troops, and to deploy them.

Choose the right gathering place

In order to be able to quickly respond to any enemy attacks, and to avoid having to fight on your territory, gathering at the right province is of prime importance. In order to choose this place, take into account:

• Its owner: gathering in your territory, or in an allied one, is most of the times preferable as it allows you to quickly disband your troops if a massive army is heading towards you, and it grants you vision over neighbouring provinces.
• Its relative risk: considering the distance to an enemy's capital, where he will probably gather his troops, choose a gathering point which is both close to the disputed region, and distant from the capital
• Its tactical importance: if your territory and your enemy's encroach each other, try choosing a gathering point from which you'll be able to intercept quickly some of your enemy's troops gathering to a faraway province. These early victories may determine the course of the war.

Bring War to them

Once your troops are gathered, try to attack quickly. With 2.8, Siege has been greatly accelerated, which allows you to benefit from the lengthy gathering of your enemy to occupy some of his provinces and get some warscore. A comes in particularly handy in this configuration.

Retinues and mercenaries are very useful in this situation. By deploying them before the war declaration at the border or in key regions, you can ensure to have the upper hand right from the beginning of the conflict. They will keep your enemy's dispersed levies at bay, while protecting the bulk of your armies and earning some early warscore through skirmishes or even sieges and assaults.

Especially in defensive wars, going on the offensive allows you to have more time at your disposal, and to take the initiative. While you'll be ravaging his country, your enemy will spend his time de-occupying the provinces you'll have attacked, totally forgetting about the provinces he's supposed to be taking away from you.

With proper use of the and traits, you may even be able to perpetually outrun an enemy outnumbering you.

By fighting skillfully on your enemy's land, you will gain precious time to call on allies. You may even be able to obtain white peace against an overwhelming enemy thanks to ticking warscore, without even fighting a single battle.

Choosing your Battles

A good general not only sees the way to victory; he also knows when victory is impossible - Polybius, Greek writer, general and politician

In order to win a war, one can hardly bypass direct confrontation with his opponent. Even while leading a war of guerilla and attrition, there is almost no other way to end the war on 100% warscore than by battling at some point. However, this doesn't mean that all battles shall be fought; as one single defeat can ruin what many victories have made.

Balance your strength

First, the regiments within your army should be organised in such way that no flank slightly overpowers the others, as if a flank collapses the situation can become very dire for the whole army. As there is no way to know the exact composition of an army's flank before the battle (we can only see the number of each type of soldiers present, and the name of the center commander), balancing your flanks will avoid bad surprises.

If a disproportion is unavoidable, then try to take advantage of it as much as possible. Place your best commanders on this flank, in order to maximise the impact of this flank of your army in battle. It will allow you to outpower even more the enemy flanks, compensating the disadvantage of an unbalanced disposition of your troops.

Gather intelligence

Thanks to the fog of war, one cannot see the enemy troops located beyond one province's distance from a territory he or his allies own at least partly or from one of his armies. Guessing the enemy's strategy can be hard, but some tactics can help you to cope with this.

Deployed commanders have the "Leading troops" icon on their portrait, and by hovering your mouse over it you will be able to read in what province they are. Doing so with your enemy's and his commanders' portraits will help you to know where they are assembled, and where they are heading.

Deploying your spymaster to one key region, such as the enemy's capital, will help you to monitor the presence of any armies, in addition to their numbers, in this specific region. It can be especially useful in a strait that you are planning to cross, in order to avoid an unexpected encounter.

Finally, deploying ships in a sea region will grant you vision over all neighbouring provinces. While not very useful when fighting a landlocked enemy, this tactic will be extremely useful when the land you target is right next to the sea, such as the Kingdom of Jerusalem when you are on a Crusade.

Never fight a lost battle

Ideally, your wars should be won without losing a single battle against your opponent. Lost battles do not only hamper your warscore, they also make you lose precious time while your troops are retreating to a faraway region, and redetermine the balance of power between you and your enemy. They are to be avoided at all cost, and this requires a sheer knowledge of the terrain, and of both of the armies engaged in the conflict.

According to the enemy's moves, you may choose to confront him or to avoid him. Only confront him when you are absolutely certain that victory will be yours, as a close defeat will make you lose more troops and warscore than a quick one.

As the AI does not take much into account terrain, luring it on a favourable ground should not be complicated, as long as your numbers are equivalent or inferior to theirs. While it won't guarantee your victory, it will at least weaken your enemy and strenghten your troops.

If you decide to avoid confrontation due to his overpowering forces, wait for your enemies' army to lose troops during lengthy sieges on your territory, while reinforcing in your land as much as you can. As long as you don't feel strong enough to rout the invading army, gather your forces and wait for theirs to diminish on your territory. It will maybe make you lose some warscore, but at least you won't lose the war.

Victory even in defeat

Sometimes, losing a battle can be counted as a successful move. If the enemy army had a hard time routing your army, and lost many more soldiers than you did during the battle, this one can be counted as a victorious endeavour. The balance of power will have been redressed, and the enemy army much more vulnerable.

In order to maximise your damage to the enemy army, some factors are to be considered. Terrain is the first one, as any bonus is good to take, even in desperate times. Troop quality also has an huge influence, especially in late game, as an elite army (one constituted of mercenaries, retinues or Holy Orders) will be routed less easily and kill much more soldiers in the meantime than other ones.

The melee phase is the turning point of all battles. Reaching, and then dominating the melee can have an huge influence over the outcome of a war. While Eastern or tribal armies will be very good at skirmishing, once you reach melee only the amount of and , along with the commander skills, will matter. , and other narrow flank and morale boosting combat modifiers become vital at this point.

A disastrous skirmishing phase can as such be compensated by a glorious melee, that will maybe not make you win the battle, but at least slaughter recklessly vast numbers of enemies.

Amphibious Operations

As CKII does not feature sea battles, the sole active use of ships a lord can make is the one of transporting his troops from one coast to another. Due to this, ships display a particular tactical depth, and the one who masters their use can hardly be beaten.

Gather your troops quickly

On the contrary of land movements, transportation by ships is extremely fast in the game. While it can take weeks, or even several months to gather your levies by land, a week or two is all it takes to do the exact same thing by ship with your coastal levies.

This can give you a considerable tactical edge over your enemies, as if your land has a good accessibility by sea (such as the Byzantine Empire), you can very easily outspeed your enemy and start your operations while he will still be struggling to reunite his levies.

Deploy wherever you want, whenever you want

Another advantage of the use of ships is that you will be granted vision over all counties neighbouring the sea region they are in. Cutting off reinforcements by disembarking between them and the main army, raid the enemy capital or surprise your enemy by disembarking your troops right in front of theirs becomes very easy with ships.

Due to their great mobility, armies embarked on ships are hard to draw in unwanted confrontation. It becomes very simple to concentrate your forces to gain local numerical advantage even against an overwhelming but dispersed enemy.

For instance, with a 15k army embarked on ships, killing off several armies of 10k soldiers raiding different parts of your empire can be very easy, as the total amount of troops become irrelevant. The only thing that matters is how much strength you'll be able to apply in one particular point, and thanks to your ships you, and not your enemy, will always have this local numerical superiority as long as the fighting takes place on a coast.

Lure your enemies

This particular tactic comes in handy when you are facing a slightly weaker enemy. Such enemies are hard to smash during battles, because the combats will end and the enemies rout even before your troops will get a chance to massacre theirs in a melee phase. In order to force them to fight decisive battles, ships are very useful.

If you leave a small contingent on the coast, and embark the remainder of your soldiers on ships, the AI will only notice this contingent and not the bulk of your army once it'll be in high seas. It won't resist the temptation to smash these soldiers before continuing its way.

The AI will then engage battle, and your land army collapse. One or two days before these are routed, comes the time to disembark your army right in the middle of the battle. After a few days, it will land, and count as a reinforcement to your routed contingent.

As such, your disembarked troops will immediately engage in melee. Given you have enough troops to win despite the Amphibious disembarkment combat modifier and/or the -50% morale your troops will have, your troops will be able to destroy utterly the enemies. Very few soldiers will survive on their side, and you'll have earned a whopping amount of warscore.

Master the land with the seas

Due to the benefits listed above, an efficient coordination between naval and land forces can grant an enormous advantage to the player when it comes to battle, while the AI is very weak on this specific point. However, naval units can also serve assymetric warfare.

When facing a very strong enemy, or after a crushing defeat, naval units may represent your last resort to overthrow the situation.

First, they can help to de-occupy terrain that is near the seas. By landing your depleted army on the rear of the frontline, and assaulting freshly lost territory, you can ruin months of siege efforts from your enemy in a week.

Second, when your war targets a coastal Duchy or Kingdom, first occupy when you land a coastal county. Then, as your occupation and battling goes on, always try to have an occupied port with your fleet in it close to the province you are in. It will provide a safe and quick escape route should an overwhelming enemy army appear to squash your forces, like it often happens in Crusades.

Last, embarking your troops systematically on ships, even if you border your enemy's land, may ensure that your troops will never get trapped again in a confrontation with an enemy army. In addition, it will greatly speed up your rhythm of operations, thanks to the extraordinary naval mobility. As such, you'll be able to quickly exploit an opportunity to weaken the domineering enemy should one appear. Time is precious when at war, and ships help you to save a lot of it.

The Cycle of War

In order to maximise your efficiency during your conquests, you'll need to be able to see when to act and how to act at anytime in sometimes very unstable conditions. Knowing the cycle of war in CKII will allow you to be victorious even in very dire situations, while preserving as much as possible your strength for future challenges.

Initiation

This phase immediately follows the war declaration, or the entrance of a new actor in the conflict. It is the phase of deployment and of the first skirmishes, and as such it mustn't be neglected if you wish to dominate your opponent right from the beginning.

Organise your army

First of all, you'll need to rally your forces, composed of your levies, your retinues and sometimes mercenaries and holy orders. In doing so, you'll have to decide which forces to use and how to divide them. Deploying and moving across the map takes time, so you'll need to decide right at the beginning of your priotities.

With a small realm, it is often better to stack up all your can in a single army. It will be easier to follow, easier to control, and anyways your resources are too limited to reasonably hope to win if you divide your forces against your enemy. Deploy your army as close to the frontline as you can, and do so as fast as possible.

With a larger empire, and especially when facing another large realm or empire, you'll need to have a higher degree of organisation. Think carefully before proceeding about which path your enemy's armies will follow to attack you, and plan accordingly. As occupation warscore doesn't scale down much with enormous realm sizes, even the loss of a single border duchy can sink your warscore by 30-45%. This, coupled to more occupation and a minor defeat in battle can mean the end of the war for you. As such, protecting all of your borders is a priority, even before thinking about attacking. The ideal army size for a campaigning army is about 15k. If you have several times this number in your troops, it might be better to create another corps to watch the border while your other corps attacks, than to send both on a hazardous expedition without protecting your territory. Place your reserve army at key points (mountain passes, large counties) from where you'll be able to deploy it quickly if ever it is needed, for instance on a coast.

Define your early campaign objectives

After gathering, you'll need to act as soon as possible. Depending on whether you attack or defend, you'll need to ensure first access, then vision over the contested region.

Access is especially important when the target is overseas or far away, for instance during a Crusade or a Jihad. Having a safe and quick access to the disputed region will allow you to send reinforcements, such as mercenaries, to the bulk of your army without suffering significant losses on the way. It will also, if the situation requires you to do so, allow for a safe retreat route and a quick access to a territory where your depleted army will be able to reinforce.

If the territory is well integrated to your empire or surrounded by allied lands, access should be ensured. However, if the targeted region is overseas, isolated or if the only way to access it from your territory is to pass by or through enemy lands, then you'll have to strengthen your position. This will require you to occupy neighbouring lands, or to take over a coastal county/duchy near the disputed region to ensure that the location of the operations' theatre won't be a problem for you.

While defending, try also to complicate the enemy's access to the land. Following the same criteria as above, occupying away from your enemy isolated or weakly connected territories will deliver a first blow to your enemy, while reducing the frontline's length and hampering his economy and reinforcement rates.

Along with access, vision is also important to have. Knowing where your enemy's armies are gathered and where they are heading will give you a significant advantage, and allow you to plan your campaign in consequence. Checking the command icons of the enemy ruler and his commanders, and following their path will allow you to anticipate the regions where their armies are heading, and then determine whether to face them or not. Deploying your spymaster or another councillor in enemy territory will give you more detailed intelligence, and allow you to choose the best option to face them.

After the initiation phase, come either the Combat or the Besieging phases.

Combat

During this part of the war, your goal is to massacre all of the enemy's armies, by hunting them down and preventing their reinforcement. This phase is the decisive one of any war, as depending of its outcome either you or your enemy will be able to take the advantage and accumulate warscore. As such, you must plan carefully when to trigger the combat part, as an untimely or reckless offensive may lead to utter disaster.

The best times to start fighting are:

• When your army is gathered and your enemy's is not, in order to profit of its dispersion.
• When defending with enough forces to challenge the attacker and none of your territories are occupied.
• When you have occupied some territory, but the enemy army is already there de-occupying the freshly conquered holdings
• When you have already accumulated significant occupation warscore by occupying the contestes region, and pursuing the besieging/assaulting would hamper your chances to repel an enemy offensive.
• When an enemy army is busy occupying your territory, and puts significant military and economic pressure on your shoulders.

Use your commanders well

During this phase, you'll need to maximise the combat efficiency of your army. commanders will be useful to deploy quickly your armies where the enemy is, and to hunt down the enemy army if it tries to escape battle. Once battle is about to begin, you'll have to choose between damage and defense commanders. Damage is useful when victory is assured, and your goal is to kill as many enemies as possible. On the contrary, defense and morale-boosting commanders will prove useful at turning the tide of war in one hopeless, decisive battle.

Preserve your strength

As a rule, never fight battles if you don't think victory is achievable, or if you don't think a defeat would still deliver a severe blow to the enemy. Your goal is to accumulate warscore, so you should always be extremely careful when choosing which armies to engage and where to engage them. One crushing defeat is enough to erase the benefits of many victories.

After the battle phase, come either the Besieging, the Retreat or the Observation phases.

Besieging

This phase consists mainly in besieging enemy holdings and liberating your occupied holdings, although you might sometimes have to engage in a battle to prevent a dangerous enemy army to ruin your efforts.

Ideal moments to trigger this phase are:

• When the enemy army is at shambles, after a successful battle phase
• When the enemy army is distracted elsewhere or still gathering, as it will allow you to reap some easy warscore
• When you only need a few more points to end the war
• When you lost many territories to the enemy, but you managed to dispose of the occupying army.

This part is the most lengthy of a war, but also the safest. If you planned your actions well, your enemy should not be a threat and the occupation go smoothly, especially with a commander.

Mind not to overstretch

The major risk during this phase is the one of overstretching your forces. Siege events, such as a sally from the defenders or epidemics may occur, and kill off around 10% of your besieging army at once, and sometimes one or several commanders. Several of these events may swing away the balance of power in the conflict, and leave your depleted army vulnerable to a vigorous counterattack. Also, be mindful not to venture too deep into the enemy's territory, as it will both make your army vulnerable to a surprise attack, and leave your home provinces almost defenceless if you didn't leave a defensive corps there.

Keep your eyes out for the enemy

Monitoring your enemy's moves is especially important during this phase, as while it takes several weeks or many soldiers to siege/assault a holding, it is very easy to recapture a recently lost territory and to ruin all of the attacker's efforts. You'll need to be able to tell at any time where the enemy army is, in order to avoid the bad surprise to see a vast territory your army took time to take suddenly liberated by an army that appeared out of nowhere while you were busy occupying some other territory.

After the Besieging phase, may come the Retreat, the Battle or the Observation phase.

Retreat

This phase follows a crushing defeat at battle, or an unforeseen reinforcement of the enemy's armies leading to a prudent withdrawal of yours. Retreat must be carefully planned, as an orderly retreat can effectively limit a disaster's significance and prepare for a prompt counterattack.

Find a falling point

First, you'll need to choose a falling point. This falling point needs to be allied or part of your territory to allow for reinforcement, and to be isolated or protected well enough to prevent the enemy from delivering the fatal blow to your forces. Ideally, it should be an island near the combat theatre (like Chypre), or any territory located at least at 4 counties from the frontline.

Prevent a collapse

Then, you'll need to ensure the retreating goes smoothly, and doesn't end up in the collapse of your frontline. If you are decisively losing a battle, it is preferrable to right-click on your falling point before the end of the battle, in order to force the army to retreat there and not on a random territory like it usually does. You'll save precious time doing so. Also, if you have a reserve army available, you'll need to redeploy it to prevent the enemy army from exploiting their victory through occupation.

While retreating, your main concern should be to prevent the enemy from exploiting your withdrawal. With the reserve army, if the enemy cannot be openly challenged, you'll have to slow it down (by running away and having the enemy army follow it) or to limit its impact, by de-occupying any holdings lost as soon as the enemy army leaves the region. If you manage this delicate part well, final victory may still be achievable.

Muster your strength

Once your army successfully retreated, try to leave it reinforce as much as possible instead of trying to counterattack recklessly. It is only when you feel it has reinforced enough to challenge the enemy army again, or if you think you can't do without it anymore, that you should redeploy it. Once redeployed, your main goal should be to counterattack and beat the enemy army, by all means possible.

After this phase, come usually the Besieging or Battle phases.

Observation

This phase is one of waiting and intelligence gathering. If you are heavily outnumbered and can't take the risk to send your armies on the offensive, then you'll have to wait for the enemy to show up and then act in consequence.

Gather intelligence and plan

Although your armies will be idle during this phase, once deployed to their defensive positions, you certainly won't. This time should be used to foster alliances, gather intelligence on your enemy's actions, recruit whatever mercenaries and holy orders you can afford to field and trying to find how to get yourself out of this dire situation before the enemy shows up. As such, this phase, although stressful, will have a decisive impact on the future operations and the outcome of the war.

Conclusion

To conclude, knowing the cycle of war will allow you to skillfully exploit the time and forces at your disposals, giving you a decisive advantage over a very often erratic AI. Managing well its different phases and the transitions between each one will preserve your forces for greater challenge, and in the end you'll be able to spend virtually all your time at war without ever being overrun by the events and the enemy forces.

Managing Diverse Conflicts

While expanding, one cannot ensure that he will always have a single enemy to face, and a single war to win. As such, he needs to know how to react when facing multiple enemies at a time, in order to both preserve its territory and prevent a situation similar to this one from happening again.

Concentrating your troops

While one can be tempted to divide its armies between the multiple fronts, in order to leave none undefended, it is most of the times a terrible idea. Your enemies' forces won't be divided, and even if you have a large enough numerical superiority to be able to fight with equal numbers on all fronts, your attention won't be able to manage efficiently such a variety of theatres and battles simultaneously and you won't be able to mobilise your best commanders at multiple places at a time. As such, troop concentrations should stay as high as they can be in order to maintain your advantage.

Your priority should be to conclude as many wars as you can in the shortest time possible. As such, you'll need to have one or two armies, maybe three, in order to have a large superiority in these theatres. Depending on your current progresses, it is up to you to decide whether to reach 100% or to crave for white peace in each conflict. The fact that you are facing multiple enemies should not change your overall war philosophy; redeployments make you lose precious time, and time is precisely what you need the most when facing multiple enemies. It is only by eliminating meticulously the moment's easiest threat to dispose of that you'll be able to reduce with minimal losses the amount of enemies you'll have to face.

But you will need also to prevent a total disaster in the other fronts, where you won't have left any serious opposition to your enemies. As such, mobility will become extremely important for your survival. If you manage to concentrate the right amount of troops at the right time and at the right place, you will eventually emerge victorious. In order to do so, ships are of the prime importance. Even if your territory doesn't stretch overseas, using them to do quick jumps along the coastline in order to redeploy on the other side of your realm will make you save a colossal and extremely precious amount of time. An will also be of crucial help, as he will help you to relocate your troops as fast as possible by land at the place where they are needed the most.

Your role in this situation is the one of a fireman surrounded by fire; you cannot just leave, and leave all be shattered by the flames. Thus, you'll need to destroy what you can do in a minimal amount of time, while preventing any threat to become so serious that you won't be able to repel their attacks. It will be up to you to strike when required, and to stave off your enemies.

Getting out honourably of unnecessary conflicts

Even if ideally, you should be able to win all your wars, there are some times where there are too many enemies, or where they are far too overwhelming to even hope to win your war against them. Luckily enough, you may be able to reach some exit doors from these, preserving your strength and attention for other, more balanced confrontations.

The first exit door is obtaining white peace. It is preferably used in defensive wars, as it will grant you some Prestige and your attacker will have a 10 year truce with you, which will keep him out of your preoccupations for a while. It is relatively difficult however to obtain it in a defensive war, as you will need positive warscore for your aggressor to accept it. On the offensive, it should be used against a faraway enemy or when your target called on mighty allies, in order to preserve your offensive capabilities for other, more important wars. Generally, as you declared war, you will have fought for some time already, and gotten some warscore, which makes white peace easier to obtain offensively than defensively. 30% warscore or more is normally enough for AI acceptance, and it can be reached even against an overwhelming enemy by quickly assaulting its demesne in a county where there are numerous cities and churches (less fortified than castles, and they give out more warscore).

If white peace is impossible to reach, due to a negative warscore and a dire military situation, you will be forced to consider surrendering against one of some of your opponents. Consider well the losses it will incur to your realm, as your goal is to spare your forces a lost and costly fight, not to weaken them more than they already are. Surrendering on offensive wars is rarely an option, as the amount of war reparations you'd have to pay will probably put you in bankrupt, which will greatly hamper your capacity to win the other wars. As such, surrendering to defensive wars is to be preferred. Surrender in priority to:

• Wars targeting a single county or holding, but which leaves you in control of the de jure duchy. Once all your wars will be ended, you will be able to easily regain control of it through a de jure claim.
• Wars against an overwhelming enemy, which has largely greater numbers than you. As your troops will have a lot of trouble facing their armies, it is preferable to surrender in order to spare their strength for more accessible foes.
• Wars targeting multiple holdings which are outside of your de jure territory. They won't be among the most productive ones, and will regularly produce rebellious vassals which will be more likely than the others to join factions.
• Wars caused by factions, as long as they are not threatening directly your control of the realm. Factions to increase council power are among these.

However, if any war which meets one or multiple of these conditions targets directly your demesne, it is preferable to continue fighting. As the core of your power, and your main source of both levies and revenue, it will have a critical role to play in your other ongoing conflicts, and losing a demesne county will slightly weaken your war effort. The only case where it is acceptable to do it is when it has the Recently conquered modifier, as it renders your province nearly useless for all its duration.

Keeping hold on your budget

When facing multiple opponents at a time, mastering your budget is of prime importance. Resorting to mercenaries might be necessary to win crucial battles when your numbers don't match the ones of your enemies; however, using large bands will be very costly, both at the time of their recruitment and over time due to their maintenance fees. As such, one must carefully consider the right time to use them, and to which troops resort. Note that they are not suited prolonged sieges; for all the time they'll be sitting around a castle to siege, you'll pay several times their recruitment cost, which may cause a bankruptcy. Mercenaries should then be either recruited for battle, or for assaulting, for the shortest period possible.

For battle, you'll have to consider that each mercenary band you hire starts with 0 Morale, slowly recovering it over time. In order to time well the time when you'll use them, you'll thus need to do it about a month or two before the actual battle, in order to leave them time both to recover their morale and to join to them the rest of your forces. When the time will come, you'll have to consider carefully to which troops you'll resort;

• Skirmishers (like most Oriental bands, and the Nomadic ones, composed of , , , ) can be very useful to crush dispersed, small enemy armies or to complement your regular army if it is composed mainly of Melee-based troops (like European and Indian ones). On the other hand, they will be weak in battle against a large or elite enemy army (as the Melee phase will be unavoidable), and also in assaults, as their melee attack value is low. They can be both inexpensive, if composed of archers and light infantry, or extremely costly, if they are based on cavalry.
• Melee-based mercenary bands (like most European ones, and Holy Orders, composed of , , , ) can be precious in very large battles, as they'll be able to slaughter hundreds or even thousands of enemy soldiers during the melee phase. They are best used in large numbers as shock reinforcements, when one or several of your flanks are retreating until they arrive on the place of battle and lock the unsuspecting enemy in a bloody melee. They are also very useful in assaults, due to their high morale, defence and melee attack. However, their cost is most of the time very high, second only to the largest steppe mercenary bands.

For assaults, there is a slight difference between skirmishers- and melee-based armies. While the first ones contribute mostly with their morale damage and high numbers, the melee-based armies form the core of the attacking force and are far more effective. The best assaulting armies are formed of and , as they have very high defence and attack potential concentrated in little numbers, allowing them to suffer less losses and thus less morale damage than . However, if you are forced to siege, it might be preferable to resort to low-quality skirmisher armies, which are both inexpensive and numerous. As troop quality has little influence over the periodic morale hit the besieged will suffer, they are the best solution to both speed up the siege while spending as little as possible.

Your budget will also have to be used in other ways than to purely supplement mercenaries. Your personal levies also have a costly maintenance fee, and often smaller realms will be deficit with them raised. This implies to either refrain their use, or to stockpile a colossal amount of money to provide for a lengthy mobilisation. Sparing a significant part for gifts will allow you to form more alliances and convince talented commanders to join your court and your armies, including the ones serving your enemies, if possible.

Also, you might have to keep some of your funds in reserve. This reserve is crucial by three aspects:

• First, it will provide a cushion to provide for unexpected expenses. When one of your demesne holdings is occupied or raided, the attacker will pillage 15-50 gold, depending on the holding type. This gold will be taken from your chests regardless of your financial situation, meaning that if you don't have the required funds, you will get bankrupt.
• Second, it will allow you to continue administrating your kingdom as if war wasn't at your doors. Many aleatory events, which are beneficial for your character (such as the Icon sponsoring one for characters), require you to pay a little amount of money. If your situation is not critical, the reserve will allow you to continue solidifying your dynasty's capacities and grip on the realm without compromising your war effort.
• Last, this reserve will be there to be used if you are forced to surrender on an offensive war, and thus to pay reparations to the defender in order to avoid bankruptcy, which can be prolonged if your income is near 0 and the other conflicts you're involved in keep on raging for a long time.

Keep in mind though that these dispositions are to be made right at the beginning of a war. If you haven't prepared, or haven't enough income to stockpile, then you'll have to manage your expenses to prevent bankruptcy. While it is merely annoying at peace, getting bankrupt in the middle of a war is terrible. Apart from the -25% morale and thus strength your troops will have, negative modifiers will pop up in your demesne, hampering levy reinforcement, levy size, tax, in short reducing by much the province's contribution to war. Unpaid mercenaries will either join your enemies, even if their troops are merged with yours (a battle will then occur), or withdraw. For 2 days, their leader will have a strong claim on your primary title, allowing him to declare an invasion on your realm. During a war, one must thus be careful with his expenses; as bankruptcy can significantly worsen an already bad military situation.

Imperium Mundi

With great empires come great responsibilities - Uncle Ben, in Spiderman

Reaching to world domination, you should quickly enough find yourself at the head of an enormous empire after centuries of continuous warring, if you knew how to fight well in all wars. Even though the threat of a game over is far behind you now, the management of a great empire present threats that, if left unchecked, may well lead to your fall or at least cause severe drawbacks in your bid for world domination, or whatever other goal you pursue.

Coping with Defensive Pacts

主条目：Defensive pact

Defensive pacts are atrociously annoying in late game. Almost any conquest you'll make will make explode your level of threat, and short of waiting 40 years between each war you'll be forced to cope with them, if you didn't deactivate them in the game rules.

Luckily enough, you have several means at your disposal to make the realm you want to target leave a defensive pact before your attack, so you can avoid to inadvertently trigger World War I 800 years in advance.

First, you'll have to be prepared financially. Check your income with all of your personal levies raised, and then depending on the amount choose mercenary bands that you'll be able to field permanently without getting deficial. Plan for a good reserve of cash, as it will allow you to pay for the lost holdings (when a holding on your territory is occupied, the attacker will pillage some gold from your treasury), and for additional mercenaries if needed.

If you choose to occupy all the territory, move the mercenaries, holy orders and retinues to the border, to start assaulting as soon as possible. Then, focus on the enemy's territory, and deploy your armies to protect on one side the territories you'll have already occupied, and on the other to steamroll as fast as possible the remaining ones. The faster you'll act, the easier it will be, and you may be able to win without fighting major battles.

Distribution of power

主条目：Distribution of power guide

With extremely large empires, the distribution of power among your vassals becomes determinant. Your empire will soon become so large that the simple divide to reign motto will become irrelevant. As such, you'll have to find new ways to organise your realm to take the best from your vassals.

Set up viceroyalties

With a growing empire, passing Imperial Administration will soon become essential to raise your vassals cap enough to supplement further conquests. Apart from the +25 bonus of vassal limit, it will also pass the "Duchy-tier viceroyalties" law. Your goal from now in intern politics should be to cancel the titles of your direct vassals and to make them viceroyalties, in order to be able to control more easily the distribution of power in your empire.

As your expansion continues, waging one war at a time won't be enough. Setting up powerful vassals at the borders, that will like you well (after you grant them viceroyal titles) will prove very useful with inner wars prohibited. They will expand on their own and push forward in your enemies' territory, saving you time and attention. Also, having powerful vassals at the border means that, if ever they rebel, they will not directly threaten your power core and will be exposed to foreign attacks and war declarations.

When creating large vassals such as multi-kings, try to ensure that each vassal can provide enough ships to carry the troops they provide. Troops that can be immediately loaded into ships can contribute to the war much sooner than troops that must start an overland trek with 0% morale. (Raise vassal troops and ships from the province view so you can control where they appear; raising levies using the military view means relying on your vassal's choice of capital.)

战争