Spells per Day: At each even-numbered level, you gain new spells per day (and spells known, if applicable) as if you had also gained a level in a spellcasting class to which you belonged before adding the prestige class level. You do not, however, gain any other benefit a character of that class would have gained. If you had more than one spellcasting class before becoming a scar enforcer, you must decide to which class to add each level for the purpose of determining spells per day and spells known.

Favored Enemy (Ex): As a member of this class, you gain a +2 bonus on Bluff, Listen, Sense Motive, Spot, and Survival checks when using these skills against humans or elves. Likewise, you gain a +2 bonus on weapon damage rolls against these races. See the ranger class feature, page 47 of the Player's Handbook.

Smite Enemy (Su): Once per day starting at 2nd level, you can deliver a powerful melee attack to a human or elf foe. You add your Charisma bonus (if any) on your attack roll and deal an extra 1 point of damage per class level. If you accidentally smite a creature that is neither an elf nor a human, the smite has no effect, but the ability is still used up for the day. At 5th level, you can use this ability twice per day. At 8th level, you can use this ability three times per day.

Sneak Attack (Ex): Beginning at 3rd level, you deal extra damage when flanking an opponent or any time the target would be denied its Dexterity bonus (except on ranged attacks, which must be point-blank to deliver the extra damage). See the rogue class feature, page 50 of the Player's Handbook.

Disguise Self (Sp): Starting at 4th level, you can use disguise self three times per day, but only to assume the appearance of a human or an elf.

Hide in Plain Sight (Ex): Beginning at 7th level, you can use the Hide skill in natural terrain even while being observed. See the ranger class feature, page 48 of the Player's Handbook.

Forgo Heritage (Ex): At 10th level, you leave behind your racial heritage. You are no longer considered an elf or a human for the purpose of beneficial or harmful effects. (You still count as a half-elf for the purpose of qualifying for this class.)

Adaptation

Scar enforcers were designed with the city of Pal Ador in mind—a place where humans and elves live in an unsteady truce with deep suspicions toward each other. You could place the Scars in any city within your campaign or have them act as a roving band of mercenaries who fight for the rights of half-elves. Alternatively, the Scars could simply be part of the local thieves guild or assassins guild, with an additional political motivation that sets them apart.