Ambush is a covert command that will prepare and execute a covert attack.
You must prepare the ambush while your target is not in the room. In contrast, backstab is a similar command that can attack someone you're not fighting without having to prepare.
It has been announced that GP usage to prepare ambush has been reduced and execution now depends on the number of hits attempted.
The ambush command has changed on June 2 2011 to make the number of attack independent from the type of weapon or specials it has. It is said to instead use other properties of the weapon for the difficulty of the skillcheck that determine how many attack attempts are made.research
Ambush can be learned at 60 levels of covert.stealth and covert.items.weapons from the recruiter in any thief guild (for thieves) or from an assassin instructor (for assassins).
The Thieves' Guild does not teach covert.items.weapons above 50 levels, but this can be bypassed by advancing covert.items.weapons to 50, then advancing covert.items by 10.
The attack must be prepared before use by entering "ambush" which takes you into hiding. Then, when a target enters the room, you can "ambush <victim>" to execute your attack. You must already be lying in ambush when the target enters the room; attempting to ambush a target who was in the room the entire time will result in a failure to attack. Upon executing a successful ambush you get up to four attacks.