Everything in the Base Game that related to personality. Packs add new ways to give depth on the sims, such as the Character values, Celeb/Vampires System, Public Image, Clubs, Careers, etc. While they add depth on the sims themselves, it will never reach the potential depth if the personality system in the base game isn't overhauled.
1. Traits - The moat fundamental and foundation of personality. Sure seasons added liking of a particular tradition based on traits making them more unique, along side with other small features in packs(such as good sims rejecting coffin wohoo, and lazy sims not putting their laundry in the basket) but if the traits are lacking in the base game itself, it will never reach its full potential. Because ad we play we are playing mostly with the base game, just added extra features with packs, but the way you socialize, your sim react, etc. Will still depent on the base game traits. Hot Headed trait in The Sims 4 does not feel hot headed at all except those reandom moodlets and when targeted with mischief. Negative traits except jelousy and perhaps the unflirty trait, does not have deep consequences and imapct on game.
If I had a sim who is Hot Headed, I should not have the same feeling when playing a Gloomy sim and a Cheerful sim.
Traits are lacking variables or enough attributes. Look at Sims Wiki and compare the difference between the Genius trait in Sims 3 over Sims 4.
2. Emotion System. This should be the second priorty when developing the game, and this system should be built of based on a Sims Traits. How would that work? The Moodlets themselves should not be based on a particular event but be based on a particular trait. What could that mean? It means that moodlets should be based on a particular trait to have a full impact on game play. A moodlet can be any emotion based on the Sims traits.
This is the best example. Say you created a Hot Headed, Neat, Loner Sim. If a sim was in a room full of dirty surrounding, he/she should feel Angry i stead of Uncomfortable since Hot Headed was the sims Emotional Trait. If I had a slob, Genius, Kleptomanic Sim, then the sim should feel Focused when the surroundings is dirty, and be focused when the sim still something. Have a gloomy, Perfectionist, Geek Sim? Then when you play that sim the sim should feel sad everytime he/she crafted an awful work, and sad everytime he looses in a video game. Thise are just trait related obvious thing that emotion system should do. It should do based on traits not on the random emotion assigned to an emotion and based on traits.
If they ever did that, Sims will feel much more unique, add that on the top of packs. You will play and feel a different sim each time you switch sims, and this alone could be the biggest innovation that The Sims 4 can do, as it adds depth not just on personality but based on the gameplay oppurtunities a player can do.
And Lastly, the Overhauled whims and Aspirations. This two can be link to trait and emotion. Aspiration should not be goal oriented, but trait sim oriented. Which means the way of completing your sims aspiration is based on what they want their whims. If a sim wants to be a writer the player should follow the whims of the sims related to writing. Not only that but also random wants the sim have. Why? Because if your sim wants to be a writer, its not just being a writer that ansim want, but a happy and helathy life. So by providing it to the sim, and completing aspiration, players could see lifetime benifits for that sim, that will make the player feel rewarded for the challenge that they
have done. And that is where traits and emotions comes into play. They will add challenge. First thing is Fear. Fear muat be added as it adds depth and consequences to the game. Fear like into The Sims 2, but better if they did this type oftrait and emotion system. A hot Headed sim who had gis fear happened, should have feel guilt and anger for himself for letting a particular event happen. A evil sim who aspires to be a writer will have the player try to give the sim a happy life by seeing other sims suffer(e.g. eating pufferfish) and with get famous, accomplishing that sim want to be infamous as possible, while trying to publish a book that he wanted to publish is going to be a hige challenge. It adds depth, and mich more uniqueness to a Sim that will make the player be encourages to trying out different traits to see different challenges in the game.
Memories System will be my last straw. I don't need a screenshot for memories, I just need the memories system function the way they work on The Sims 2. With overhauled Traits, Whims, and Emotions Memories will add a much more deeper on personality. If a sim, for example encountered a negative memory/positive memory but is associated with a negative emotion, the sim will try to avoid a particular action that caused it. If a sim married but hot rejected at the altar, a sim will recieve a emotion based on trait(If the emotional trait is not negative then a sad emotion) such as a hot headed wife will be angey inatead of sad, then the sim will try to avoid marriage as possible and the player will have to direct the sim to marry to do it again. For example after being rejected, a sim will cry for nights before movong on. Or even better, to overcome a particular memory, the player will do a positive actions to help the sim move on, such as take the rejected sim to the night club with their sim, and as he/she becomes happy, he can move on trough a cariety of options/social actions. Then it will be a much more challneging with negative traits, such as gloomy sims may not move on at all or have a slow ppgase of time before moving on.
Do this in The Sims 4, and I believe in my perspective that this will change how people play the game in Live Mode. The game will be Full of Emotions, full of life. This level of personality depth have come closer woth The Sims 2, and now by doing overhauls I think The Sims 4 is going to surpass how depth The Sims 2 has, especially since The Sims 4 had packs that was well received for its great impact on gameplay such as clubs, the vampire weakness, celebrity quirks, a potential hobbies pack, active careers and much much more. This is the greatest potential that I think The Sims 4 could achieve.
