|Benefit: If you have been prone since the end of your last turn, you can ignore the penalty the prone condition imposes on ranged attack rolls you make using a crossbow or firearm with which you have Weapon Focus.|
The character is lying on the ground. A prone attacker has a –4 penalty on melee attack rolls and cannot use a ranged weapon (except for a crossbow). A prone defender gains a +4 bonus to Armor Class against ranged attacks, but takes a –4 penalty to AC against melee attacks.
Standing up is a move-equivalent action that provokes an attack of opportunity.