Abilities

Abilties can refer to several things.

In The Witcher, there are basically three kinds of abilities and some statistics which can affect them.

Character interaction

 * Geralt has some basic abilities that he uses just to interact with the people or NPCs he meets in the course of the game. These are called character interaction abilities, and they include:
 * bribing or simply paying people
 * buying items from and selling items to merchants
 * drinking contests
 * fistfights
 * giving gifts
 * having weapons forged
 * meditating
 * playing poker
 * storing items
 * using signet rings

Character development

 * Geralt can acquire many unique witcher abilities by the allocation of talents that he gains through experience. These are called character development abilities, and they include:
 * learning and using witcher signs
 * improving swords skills for both steel and silver swords
 * improving attributes like intelligence, strength, stamina and dexterity

Character statistics
There are also factors which govern how well Geralt can perform some of the skills he has, particularly in combat. These are called character statistics and they include:
 * Vitality
 * Endurance
 * Toxicity

In The Witcher 2, there are distinct abilities which modify Geralt's stastics.

Abilities

 * Geralt can learn several abilities by performing specific actions and interacting with various NPCs in specific ways. Axii Sign Hex, Intimidate, and Persuasion all have three levels; all other Abilities have only one. These actions and how to acquire them (spoiler alert) are listed below:
 * Pyromaniac - "Critical effect chance: incineration +20%." Receive a certain amount of damage by being set on fire. Set Geralt ablaze by walking into a campfire and repeat approximately 20 times (Ability Level: 1).
 * Assassin - "Damage dealt by attacking from behind: +25%." (also listed as 'Backstabber' in some versions of the game). Find the dead Altaïr Assassin's Creed lookalike next to some hay in the courtyard near the ballista during the Prologue (Ability Level: 1).
 * Axii Sign Hex - "Allows the use of the Axii sign during conversations to obtain information or other benefits." Use the Axii sign during specific conversations like Geralt's interactions in "Woe to the Vanquished" or with High Priest in the Temple during the Prologue (Ability Levels: 1-3).
 * Intimidate - "Allows the use of intimidation during conversations in order to obtain information or other benefits." Use the intimidate option during specific conversations like Geralt's interactions in "Woe to the Vanquished" during the Prologue or during the Kayran incident in Chapter 1 (Ability Levels: 1-3).
 * Persuasion - "Allows the use of persuasion during conversations in order to obtain information or other benefits." Use the persuasion option during specific conversations like Geralt's interactions in "Woe to the Vanquished" during the Prologue or during "A Dream Shop" in Chapter 1 (Ability Levels: 1-3).
 * Conjuror - "Signs damage: +3." Automatically given upon reaching the Temple during the Prologue (Ability Level: 1).
 * Strong Back - "Geralt can carry more items. Total Capacity: +50." Spare Aryan La Valette and help him "escape" the La Valette's dungeon during the Prologue. It will be awarded upon exiting the dungeon (Ability Level: 1).
 * Cover - "Damage reduction: +10%." Stay under Triss's protective umbrella without exiting during the begining of Chapter 1 (Ability Level: 1).
 * Strong Stomach - "Resistance to critical effect: poisoning: +10%." Drink Ostmurk Potion and defeat Kayran during Chapter 1 (Ability Level: 1).
 * Thrower - "Damage dealt by throwing knives: +5." Defeat Ves in a knife throwing contest during the party at the Blue Stripes hangout in Chapter 1 (Ability Level: 1).
 * Anatomy Lesson - "Damage against humans: +10%." Examine the body in the catacombs during "With Flickering Heart" quest in Chapter 2 (Iorveth's path) (Ability Level: 1).
 * Birdman - "Damage against harpies: +10%." Destroy all 7 harpy nests in "The Harpy Contract" quest during Chapter 2 (Iorveth's path) (Ability Level: 1).
 * Child Of The Night - "Vitality regeneration at night: +2." Sneak through the camp undetected during the "Where Is Triss Merigold?" quest (Iorveth's path) near the end of Act 2 (Ability Level: 1).
 * Haggling - "-20% to price of items in shops." Gained in Chapter 2, possibly from dealing with Relic Merchant. (Ability Level: 1)
 * Swordsman - "Damage caused during sword fights: +4" (Ability Level: 1)
 * Exorcist - "Damage against all spectres and wraiths: +10%" (Ability Level: 1)
 * David - "Damage dealt to opponents much bigger then Geralt: +10%" (Ability Level: 1)

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