An action block is a script which can control many aspects of a mission's gameplay. Indeed, almost all effects seen during a mission are controlled by multiple action blocks. Unlike many scripting languages, action blocks are not typed; they rely on 256 precompiled actions which, when combined, allow for complicated effects.
Action blocks are procedural; they start at the top and step down through each action to the bottom. The flow can be interrupted by actions which divide them into loops; a number of actions are included which allow for loop control. Loops are labeled with a hexadecimal value, which allows for identification, but multiple loops can share the same value. Many actions test a condition, and go to a specified loop when true. If multiple loops share a label, the first one down from the action that preforms the test will be used. The exception to this is action $01, which returns to the beginning before stepping down to the specified loop label. All blocks end with action $04, a terminator.
Types of Action BlocksEdit
This type of block is identical to 04XX, except for the fact that they're prewritten and available in every mission.
These blocks are exclusive to Perfect Dark, and are used by the Cinema menu.
These blocks operate independently of guards or objects. They are usually used for things that have an effect on the mission as a whole, such as starting a timer or ending the mission.
Another Perfect Dark exclusive, the purpose of these isn't well understood at this time. They are used in place of the intro block to give Joanna her starting equipment (with the exception of her starting weapon).