Hello all. Welcome to my CKII Roleplaying Guide.
I have written this guide based on my own experiences with CKII, and it is designed to enhance roleplay-based gameplay. This style centers around decision making rooted in your character's education, personality, relationships, and culture. Min/maxing and rapid takeover of territory will rarely, if ever, happen. Your character is not a series of divinely controlled puppets bend on world domination, they are a person with specific interests, likes, dislikes, friends, enemies and obligations. They follow these specific motivations in life, and when they die a new person with new motivations takes over. This means that how you play often changes with each new character. If your warmaster king is succeeded by a bookish, shy one, you'll probably start investing gold in libraries instead of mercenaries.

That being said, this guide is not meant to be an ironclad list of do's and don't's. It is intended as a set of guidelines for roleplayers to help them craft a more consistent roleplaying experience. This is not intended to accurately portray how real life humans think and interact, but create a more dynamic experience that changes from character to character. Certainly, many figures have defied expectations and risen above the role they were expected to play.

Below, we'll examine each of the four categories I described above, and how they affect your gameplay. Other sections will likely be added for certain cases.

A character's education is the lense through which they see the world. It shapes how they move through the world and what their primary interests are. A martial character conquers, a steward builds, and a spy schemes. While these are fairly obvious, it's important to try and see through your character's eyes. The general will see an enemy kingdom as a foe to be crushed, while a diplomat might make a strategic marriage to secure peace and give his children claims. A spy might support plots to assassinate the enemy king. A scholar might scheme to get his rival excommunicated. Understanding how each education path interacts with the game world will help you make decisions more consistently.

Below, we'll go through each education path and talk about how the different levels affect decision making, and we'll touch on the basics of choosing your Way of Life based on your education.

General Notes
One thing that is important to keep in mind is that the stronger a character's affinity is for their education, the more likely they are to engage in activities associated with it. A lvl 1 indulgent Wastrel is far less interested in the flow of money than the lvl 4 Midas Touched. This affects general competency, as well as how focused they are on activities and Ways of Life relevant to their education. The Indulgent Wastrel is far more likely to spend their money carousing with friends than improving markets, while the Midas Touched is more likely to invest in trade opportunities and improve his vassal church's tax base. Keep in mind that stat points also play into this calculus. A lvl 1 spy with an intruige of 30 will be far more focused on scheming than a lvl 4 spy with an intruige of 12. But in general, strong education is more likely to produce strong characters.

Diplomacy
A character with a Diplomatic education sees the world through relationships, claims, and alliances. They want to be in the most advantageous position to pursue their goals, and see marriage as a primary tool to do that. These characters are most likely to spread their dynasty through marriage, and most likely to marry their heir for land. They will be the most likely to seek alliances through marriage or other means. As one of the two social-oriented educations, personality plays a more prominent role than most, and will more strongly affect your character's interests and play style.

1-2 lvl Diplomacy A low-level Diplomat understands that good relationships are the foundation of success, and securing good marriages is the key. They want to see their family prosper, and they want to ensure that their realm is not threatened. They do not aspire to unite warring kingdoms, but to have peace with their neighbors and modest marriages. They are likely to take Family or Carousing, but really any Way of Life with a strong social aspect that aligns with their interests, like Hunting. As a vassal, they will seek peace with their neighbors, marrying into their families when possible, without specifically looking for ways to spread their dynasty. They will look for ways for their heirs to inherit land, but without seriously fragmenting the realm, focusing on nearby titles or titles under the same liege-lord. They might go to war against weaker foes, or with allies at their back, to pursue strong claims or Holy Wars. They will also try to reconcile with angry vassals.

3-4 lvl Diplomacy High Level Diplomats know that relationships are the key to power, and marriage is the most powerful weapon of all. They will always seek the most advantageous marriages for their heir, gaining land for their dynasty's demesne, or giving claims to important kingdoms. They will constantly spread their dynasty through marrying sons to landed titles. Daughters will be married for the most advantageous alliances. As with the low-level diplomat, Carousing is a common Way of Life, used to gain friends and influence others. But the diplomat may choose other social WoL, such as Business or even Intrigue, if their talents and personality bend that way. They will likely go to war frequently in pursuit of claims or de jure territory, but will only attack equal or stronger opponents with a bevy of allies to back them up. When dealing with vassals, they will try to befriend strong vassals and placate them with council positions, bribes, and honorary titles. They will also attempt to break characters away from factions, either through friendship or intrigue decisions. As a vassal, they will join factions to boost council power, and are more likely to join a faction to replace their liege if they dislike him and like the pretender more. They are likely to neglect improving their demesne, preferring to spend money on feasts, hunts, summer faires, and bribes. If they have a windfall, they will most likely use it to first create status objects(thought a smith), but they may spend it to create new baronies, especially if they have high stewardship. They are also likely to "discover" claims on enemy's territory, especially if they have an amoral personality.

Martial
A ruler with a Martial education primarily sees the world as conflict and struggle, and desires to be on top. Martial rulers will engage in the most offensive wars, and will be more likely to attack large targets and take risks in warfare.

1-2 lvl Martial A low-level Martial character understands that bigger armies are better, but may not appreciate the subtleties of commanding armies, or how different troop types interact. They will engage in wars, and defend the realm, but they may not have the vision or skill to pull off great conquests, or train themselves to be a truly great warrior. They are more interested in securing what they have or what is rightfully theirs than seizing new lands. They are more likely to take Hunting as a Way of Life, and more likely to let secondary interests shape their Way of Life. As a vassal, these characters will likely follow their instincts when deciding whether to support their lord or not, but they will rarely lead revolts, or engage in wars independently without a clear claim or overwhelming strength. As a ruler, they will be more cautious and less likely to start wars with evenly matched or stronger kingdoms. When they do go to war, it will be for de jure territories, strong claims, crusades, or minor Holy Wars against weak infidels in or bordering de jure territory. When it comes to administering the realm, they will focus on improving walls, Heavy infantry and cavalry buildings. They will not generally improve keeps, muster fields or markets.

3-4 lvl Martial High-level Martial character is a master of all aspects of warfare. They will be bigger, bolder and more aggressive than their lesser trained brethren. They want to cover themselves in glory and add new territory to their domain. They will normally take Warfare as their Way of Life, and choose martial ambitions. As a vassal, they will be more likely in engage in independent wars against equal or stronger opponents, and are more likely to play an important role in a rebellion against a hated liege. If they have a high intrigue stat, or devious personality traits, they may not be above fabricating claims. As a ruler, they are the most likely to declare wars, and most likely to pursue large claims or weak claims, and are most likely to fight for territory outside their de jure lands, especially if there is a repeatable casus belli, such as Holy War. When administering, they are more likely to spend money on support buildings such as muster grounds, keeps, and militia fields. If they have a high stewardship stat, they will also improve low level markets, and if they have an especially large windfall, they might build a new barony. They will also have large retinues.

Stewardship
The Steward sees the world as a ledger. Wealth means power, and only by nurturing that wealth can a lord rise to prominence. Stewards are the most likely to invest in their desmesne and build new holdings. They are also the most likely to build trade posts. Learning pairs strongly with Stewardship, and a character that combines the two will massively boost his realm's prosperity and technology. This is also one of the professions where low levels most profoundly affect gameplay. Managing a realm's economy is a difficult thing to do, and characters that lack a strong understanding simply won't be very interested in growing their wealth.

1-2 lvl Stewards
The low-level steward wants money, but lacks more than a basic understanding of how to get it, and will generally spend it quickly. They will upgrade buildings that directly give them money, especially villages, but will rarely invest in trade that does not extract more money directly from their posts, and will likely not build new posts in their demesne. Unlike other low-level professions, this level of stewardship will rarely take either stewardship-focused WoL, preferring more indulgent activities like Hunting or Carousing or Seduction. They simply lack the discipline required to effectively manage their realm. A "good" steward with many virtues or the Just trait may take the Rulership WoL out of desire to become a better lord. They may pursue wars against weak opponents, but are unlikely to engage in large offensive wars even with a strong claim. They are also likely to engage in minor social activities like hunts, feasts and faires.

3-4 lvl Stewards
A high-level steward is a master of coin and trade. They understand how to spend and grow their treasury. They will prioritize wealth-generating buildings and trade posts for upgrades. They also improve walls and defenses regularly. They are the most likely to build new holdings in their counties, but especially cities. They will normally take the Rulership WoL, and diplomatic-minded or Merchant Republic characters are also likely to take Business. The Steward will fight wars regularly against weaker opponents, but will only go into a major war with a strong warchest, possibly with a company of mercenaries in tow. This character will always have the greatest cashflow of any character. They are also likely to upgrade vassal holdings, starting with barony holdings in their demesne or vassals they like. They will regularly engage in summer faires or activities that boost their demesne prosperity. A greedy steward may have a dark side, and prefer more illicit ways of making money. They may imprison and banish wealthy landless characters to seize their money, or even kidnap the wealthy for ransom.

Learning
Learneds come in two varieties. The godly Learned is devout, wanting to strengthen the faith and improve their own moral compass. The worldly Learned is a explorer of the world's mysteries, wanting to improve technology and share their discoveries with the world. Both are most likely to write books and join secret societies. This education path is one that is highly personality driven, second only to the Intriguer.

1-2 lvl Learneds
The Low-level Learned is, as with many other low-level educations, indulgent and undisciplined. They may or may not be concerned with study, depending on their personality. They may never touch a book, or join a society. They are more likely to choose Carousing, or Hunting than the Learning WoL. Without a focused set of traits, they may feel undisciplined, and be particularly personality driven. They will likely be more internally focused than the typical character, but otherwise will likely feel "generic". A devout character may seek to improve their godliness through charity, and if they are inclined may join a society and take the theology WoL, though they may not rise high. A worldly character may be lost, especially if they can't join the Hermetics.

3-4 lvl Learneds
By contrast, high-level Learneds are powerfully focused characters, often to the exclusion of all else. Devout Learneds will join a Holy Society, and are most likely to pursue sainthood/enlightenment. They often have traits like Zealous, but simply lacking traits that point to a worldly character is also common. They will exhibit virtuous traits and best embody the tenets of their faith. Occasionally, this may result in them pursuing their own truth and embracing heresy, especially if their personality inclines them to stubborness or arrogance. They will regularly engage in theological debates with available characters, and try to convert their court and others to their religion. They will also prioritize good relations with religious leaders over other characters. They will prioritize building new bishophrics, if they have the money and inclination. They may go to war against religious enemies, but will rarely war against brothers of the faith without a strong claim.

Worldly Learneds seek to unlock the mysteries of the earth and the heavens. Worldly characters are often defined by traits like Erudite, Cynical, and by having sympathy for other religions. They will usually join the Hermetics, and take the Scholarship WoL. They are most likely to write books on subjects they are skilled in. They will prioritize investing in buildings that spread and generate technology. They are also most likely to accept members of other faiths into their court, and employ them as councilors. They are unlikely to pursue wars of any kind, preferring to develop their lands or spend money in their pursuit of knowledge. They are also most likely to pursue tech goals that allow them to expand tech buildings.
High Learning characters synergize well with stewardship, and can make up for many deficiencies in that skill, as they substitute knowledge for practical experience. The Rulership WoL is common for Learneds, especially if their skills and traits already point to that.

The Intriguer is the most personality driven of all the educations, and thus is the most difficult to write for ahead of time. A moral intriguer(while likely a bad spy) will focus their energies on enemies to their liege and kingdom, while an amoral Intriguer will seek power and gratification. To best play this role, follow your character's personality when picking targets and plots. Intriguers of all skill levels often take the Seduction or Spying way of life.

Lvl 1-2 Spies
Low-level spies are largely driven by their personalities and relationships. They pursue petty, personal vendettas against people they don't like, or short term pleasure and wealth. They primarily target rivals and anyone they dislike. Their plots usually follow these lines, though they may fabricate claims against someone weaker than them, or if they don't like them. They often take the Seduction way of life as a way to get back at rivals and fulfill their own desires.

Lvl 3-4 Spies
Similarly to high-level diplomats, these spies tend to take the long view. They will try to build up their power as much as possible without open conflict. Amoral spies will happily murder their way to the top. Their schemes are wide ranging and will regularly combine marriage with espionage. Be wary of them. They often take the Scheming Way of Life to further their aims.

While there are too many personality traits to examine their effects individually, I will speak broadly about how they affect characters, and highlight traits that I think are particularly important for character behavior.
Most traits only come into play during events, and not during day-to-day activities. Every time an event pops, open your character sheet. Think about what your character would do, using their traits as a guide. This may not always be easy, especially for characters with an underdeveloped or contradictory personality.
In general, characters with more sinful traits will be more self-indulgent, mean spirited, and short sighted. They will likely struggle to win over vassals and courtiers. They may have a shorter than typical life expectancy as a result. Characters with virtuous traits are more generous, forgiving, and magnanimous. They will likely give away more wealth, and while on the whole may be better liked, they could be vulnerable to malcontents if they lack a skilled spymaster.
I recommend always choosing event options that become available with a specific personality trait. It's part of your personality after all!

Highlighted Traits
Ambitious: The most powerful trait, ambitious characters act most like the min-maxing characters that this guide is designed to provide an alternative to. They crave power and status, and will stop at nothing to get it. They will constantly pursue more titles, land and power. They will elevate their rank as much as possible, and are the most likely to create new titles to allow them to do so. They are also most likely to break precedent, reform religions, and establish primogeniture and agnatic-cognatic(or fully cognatic, or enatic) succession. If they dislike their liege, they will try to overthrow them or become independent, particularly if they are not a de jure vassal. If they do like them, they will try to gain power internally and otherwise try to make their family close to the ruler.

Content: The opposite of ambitious, content characters don't want to expand their position or enhance their power. Their goals are modest, and their impact small. They will focus on their own territory, and will rarely expand. They will never create a new title higher than their current one. They will not break precedent except to avoid ending the dynasty. Content rulers may be a blessing in disguise, and they focus on self improvement and improving their realm, which may have been neglected in the past. Or they could while away the time with feasts and hunts. At times it will be frustrating to play as a Content, as some opportunities will slip you by. This is all part of the experience.

Zealous: Zealous characters are fanatics of their faith, and will engage in more Holy Wars, and persecute characters not of their faith. They will be constantly ordering conversion of provinces and characters. They will take actions that are condoned by their faith. If Pagan, particularly one with a Martial education, they will make war to reclaim Holy Sites, and ambitious, high-Learning characters will attempt to reform their faith. They will want a good relationship with their head of religion, and will avoid antagonizing the religious establishment. If there is a religious holy order or secret society, they will join it if eligible.

Cynical: Cynical characters are skeptical of their faith's teachings and the priests who teach them. They will be more likely to pursue choices that clash with the religious establishment. They may still pursue Holy Wars, but they won't prioritize them over other conquests as the Zealous character would. They will simply treat it like any other war. They also won't be interested in Holy Sites. They won't care about converting provinces or characters.

Insanity: It can be hard to depict an insane character. It is simultaneously restricting and freeing. I usually do this by magnifying personality traits and skills to extreme lengths, even if it is self-destructive. Pursue claims you cant possibly win, build mausoleums to your cat. Murder those that love you. Do what feels fun.

A Note on Repeatable Decisions
One thing I do to distinguish characters, particularly if they have a relevant trait, is marking certain events as important, so I don't have to keep checking when the cooldown is over. For example, I often have my charitable, kind rulers regularly give to charity.

Please keep in mind this guide is explicitly intended not to help you grow quickly, but instead help you make a rich, unique experience for yourself. I often start as an OPM count and its common for my dynasty to remain in its single county for generations. Keep that in mind as you play and have your character participate in the system they live in. You are playing a life, and not a collection of stats

Please comment if you have suggestions to improve the guide or a topic area you think should be covered in this.