Charisma affects how well you get along with people. Game-wise, it affects prices, performance and prostitution income, and the number of pets who can accompany you. Every character may have at least 2 pets, plus one more pet for every five charisma starting from 10, up to a maximum total of fifteen pets. Pets assigned as shopkeepers, breeders, told to stay at your house (including maids), and pets waiting in town, all count towards this total.
Companions gained in escort quests count towards this total, so if your party is full, you can not do these quests.
Special actions that use Charisma include Cheer, Eye of Insanity, Eye of Dimness, and Insult. Improved Charisma will increase effectiveness and duration of these abilities. In Elona+, you can learn Directive and Call Familiar with a high enough charisma, and more charisma-based actions are added: Platinum song used by the Goose's Evolution, Eye of Brainwashing, and Gold Rush.
Upon increase: "You enjoy showing off your body."
Upon decrease: "You start to avoid the eyes of people."
How to train it
Charisma can be trained by eating certain foods, training the Charisma-related skills of performer, investing, or negotiation, Charisma-based special actions, especially the feat Cheer, or by engaging in prostitution.
Eating a putit (normal or red) or cupid of love can give a massive (half a point of charisma if you have 100% potential) boost to charisma, but a small (1% of a point of charisma at 100% potential) boost to charisma can be gained through eating much more commonly available fruit. Capturing a putit in a monster ball and breeding them can be a farmable method of obtaining lots of putit meat. Remember that high-quality cooking boosts the effectiveness of these gains.
Cheering for your pets trains charisma per use, and only costs SP, meaning you can train Charisma safely from your house or a town or any other place you can rest frequently.
Once trained sufficiently, spamming performer can possibly be the easiest and safest way to gain plenty of charisma.
"Having a little tail" with NPCs will decrease Karma (-1), has a small chance to make you sick, increases relationship with the NPC, and nets you some money. The amount of gold "earned" is dependent on your charisma, current relationship with involved NPC and some random variable; (usually other prostitutes have more money, and give a bigger return which means the variable may be how much money the NPC has.) up to all the gold currently held by the NPC. You're promptly told by the NPC if they cannot afford the full price when it's done. "It's all I have."
You can also "buy" a prostitute, which will cost you money and inflict temporary insanity, but train Charisma. Paying for a prostitute has the notable benefit of avoiding the karma penalty, so it can be done more frequently, if you have the cash and blessed healing potions on hand to cure the diseases you will catch. If you own a pet prostitute (through using a monster ball or rod of dominate), this money goes straight to the pet to buy his or her own potential increases at the same time that it boosts your charisma. (Although you risk getting a disease from - or giving one to - your own prostitute by doing this.)
Since Elona+ 1.15, it is now possible to train charisma by eating raw equipment with charisma boost on it. As engagement rings all have +5 charisma base, it is possible to use scrolls of inferior material on engagement rings to make them raw. If you buy the engagement rings from Moyer the Crooked and the scrolls from magic vendors, you will even train charisma by using Negotiation. It is recommended the first raw engagement ring you eat also maintains charisma, as that will increase your charisma potential temporarily after eating it.
(side note: pets don't seem to train charisma by eating engagement rings you try to take from them)
Skills that train Charisma
|Strength||Tactics · Two Hand · Weight Lifting · Long Sword · Axe · Martial Arts · Scythe|
|Constitution||Healing · Mining · Shield · Heavy Armor · Medium Armor · Carpentry · Blunt · Polearm · Stave|
|Dexterity||Lock Picking · Dual Wield · Light Armor · Evasion · Tailoring · Pickpocket · Jeweler · Disarm Trap · Short Sword · Bow · Crossbow · Throwing|
|Perception||Stealth · Sense Quality · Detection · Fishing · Eye of Mind · Greater Evasion · Marksman · Firearm · Analysis (Elona+)|
|Learning||Literacy · Memorization · Alchemy · Anatomy · Gardening · Cooking · Gene Engineer|
|Will||Magic Capacity · Faith · Traveling · Riding · Eye of Mind (Elona+)|
|Magic||Meditation · Casting · Magic Device · Control Magic|
|Charisma||Negotiation · Investing · Performer|
|Speed||Swimming · Traveling (Elona+)|