Flaws are like the flip side of feats. Whereas a feat enables a character to be better than normal at performing a task (or even to do something that normal characters can't), a flaw restricts a character's capabilities or imposes a penalty of some sort.
A player may select up to two flaws when creating a character. After 1st level, a character cannot take on additional flaws unless the game master specifically allows it (for examples of times when doing this might be appropriate, see Character Traits). Each flaw a player selects entitles his character to a bonus feat. In other words, when you create a character, if you select two flaws, you can also take two bonus feats beyond those your character would be normally entitled to.
Unlike traits, flaws are entirely negative in their impact on a character's capabilities.
You can create new flaws, but be careful: Flaws can unbalance your game. When creating flaws, keep a few issues in mind:
Each of the flaws described here has a specific game effect. Some flaws can only be taken by a character who meets a special requirement.
You are unathletic and uncoordinated.
You take a -2 penalty on Strength-, Dexterity-, and Constitution-based ability checks and skill checks.
You are thin and weak of frame.
Subtract 1 from the number of hit points you gain at each level. This flaw can reduce the number of hit points you gain to 0 (but not below).
You must have a Constitution of 4 or higher to take this flaw.
You are particularly unaware of your surroundings.
You take a -4 penalty on Listen checks and Spot checks.
You are sickly and weak of stomach.
You take a -3 penalty on Fortitude saves.
Your vision is obscured.
In combat, every time you attack an opponent that has concealment, roll your miss chance twice. If either or both results indicate that you miss, your attack fails.
You are relatively inept at melee combat.
You take a -2 penalty on all melee attack rolls.
You are weaker in an attribute than you should be.
Reduce one of your ability scores by 2.
You cannot take this flaw if the total of your ability modifiers is 8 or higher.
You often zig when you should have zagged.
You take a -3 penalty on Reflex saves.
You are relatively poor at ranged combat.
You take a -2 penalty on all ranged attack rolls.
You move exceptionally slowly.
Your base land speed is halved (round down to the nearest 5-foot interval).
You must have a base land speed of at least 20 feet to take this flaw.
You are slow to react to danger.
You take a -6 penalty on initiative checks.
You are not good at defending yourself.
You take a -1 penalty to Armor Class.
You are highly suggestible and easily duped.
You take a -3 penalty on Will saves.