Unexpected Attack

Assuming that a character has successfully concealed himself, he may then attempt to make an unexpected attack. Unexpected attacks are either an Ambush or a Surprise Attack.

Ambush
An ambush is defined as an attack against a target completely unaware of the attacker’s presence — generally only possible during the first round of a fight, against a target with a lower Initiative value than the attacker.

An ambush attack completely ignores the target’s Defense; the target is considered to have Defense 0 against the attack.

Surprise Attack
A surprise attack, is an attack launched from hiding against an opponent who knows he’s in battle and who is actively on the lookout for attacks, even if he isn’t sure exactly where all of his opponents are at the moment.

A target faced with a surprise attack suffers a -2 Defense penalty against that attack.

Stealth attempts while already in combat are made with a -3 penalty.