Greetings!
Today I would like to talk to you about some of the ways you can gain the Grace of the Emperor, and ways in which you can use it to your advantage! To interact with China you must be within their diplomatic range - which extends throughout the entire Silk Road, and through the influence of the Western Protectorate and any Tributaries China might have. When you are within diplomatic range you have the options to Pay Tribute and Ask for Boons.
Paying Tribute to the Emperor will get you in their good Graces, giving you the option of asking for Boons. While the first thing that comes to mind would be to become an actual Tributary State to China, there are more ways to earn Grace. Of course, being a Tributary State is one of the most effective ways to earn the Emperors good Grace - having the Emperor like you more for each month you stay a Tributary State - though you have to give up a significant portion of your Wealth and Levy Regain rate. As China prefers their Tributaries to keep paying Tribute to them, they are willing to defend their Tributaries from outside threats - Tributary States will have the option of summoning a regiment of Chinese forces when they are under attack. When playing as a small realm in the Tarim Basin, for example, it is very prudent to become a Chinese Tributary as they will help you fend off ravenous Nomads and expansionist Tibetans alike.
Not everyone will have the opportunity (or want to give up their sovereignty) to become a Tributary State though, in that case there are other things you can do to earn the Emperor’s good Grace. The two most common things the Emperor requires are more Concubines for the harem and more Eunuchs for the administration. If you are able to find characters that suit either role, you will be able to send them off as Tribute. These characters will most often have to be your close relatives, making the choice whether to send them away or not more tactical (perhaps you’d rather keep your daughter for forming a local alliance, or keep your third son as a backup in case your first two sons bite the dust). Note that you won’t be able to send off characters that stand to inherit titles. The selection of a suitable character is made by executing a new type of ‘third party character’ decision, as can be seen in this screenshot:
There are also other things you can do to gain the Grace of the Emperor, I won’t go into too much detail, but they include things such as: Offering a Court Physician when China is suffering a Plague, sending Relief while China is suffering a Famine, sending Artifacts or Gold, and more.
Any Grace you’ve earned will persist as long as the same Dynasty sits on the throne in China - Civil Wars and Invasions might result in a new Dynasty taking the Dragon Throne, making you lose any grace you’ve accumulated. Fortunately the Dynasty changes seldomly, and you get ample warning before it happens (so that you get a chance to leverage the Grace you’ve accumulated with the current Dynasty).
Emperors, like most characters in CK2, have their own personalities. This is characterized through the Emperor’s likes and dislikes - if the Emperor favors Buddhists you will find it more rewarding to both be a Buddhist yourself, and to send the Emperor Buddhists as tribute. The opposite is true for being disliked by the Emperor - with the additional threat that they might, just might, treat you as a priority target should they become expansionist!
Now on to using Grace - if you’ve sent enough Tribute to the Emperor you will be able to request Boons. Boons are generally very powerful, and come in many flavors - I won’t go through all of them in this DD, but here are a select few:
Request Peace Deal - The most basic of all Boons, having an active Peace Deal will prevent China from ever targeting you with wars. It is very cheap to get one and, unless you’re taking a risk by saving up for something costly, you should usually be able to afford one. A Peace Deal lasts for a long time, and also persists through multiple characters should the one who requested it die. In addition to preventing the wrath of China, it also gives quite a bit of passive prestige. Do note that if China is in an Expansionist phase they might not want to hand out any Peace Deals, so get them while you can…
Request Strategist - This Boon has a character trained in Chinese Strategy join your court. This character is both a competent commander by himself, but will given time also train your existing commanders in the art of Chinese warfare. This is represented by special Commander Traits with very powerful bonuses.
Request Master Engineer - This Boon has a masterful Chinese Engineer join your court. For as long as this character stays employed, he will improve your demesne with powerful province modifiers - Blast Furnaces, Paper Mills, Fireworks Guilds and other wondrous things. These modifiers tend to help you advance in Military and Economic technology.
Request Imperial Marriage - The Emperor has many daughters (and in the case of female rulers, cousins and kinsmen) and if you stand in their good Graces you might be allowed to have you or one of your children marry one of them! Such a marriage is not only very prestigious, because a princess doesn’t leave China alone - along with her she will bring a regiment of Honor Guards that you can call upon at will. Unlike the troops you can call upon from being a Chinese Tributary State these Honor Guards can also be used in offensive wars - giving you an edge in warfare. An Imperial Marriage also sets a Peace Deal in place.
Request Invasion - This is the most costly Boon of them all, and will be a challenge just to gain enough Grace for - if there is a realm that has grown too large and powerful for their own good, you can suggest that China invades them with the sole purpose of dismantling their realm. Of course, it might not be very likely that China would succeed in taking down a distant Empire (i.e. Byzantium) and there is no absolute guarantee that they will win regardless. If you are independent you can choose to join in the war yourself, which is especially useful if you really want the war to succeed. Having Peace Deals with China will protect characters from Requested Invasions and normal invasions alike.
There are plenty of other things you can request; Scholar-Bureaucrats, Siege Engineers, Chinese Artifacts, Silk Road Trade Contracts and more - but I won’t go into more detail in this DD!
Finally I’d like to say that many of these features will be controllable by Game Rules. If you want to disable the Diplomatic Range of China and gain Grace as a count in Ireland you will be able to do so - the same if you do not wish to have China launch any invasions, along with many other things. And as always, if you have any ideas/questions/concerns for Game Rules relating to the features presented in the DD, feel free to suggest them here!