DLG file format

BG1, BG1: TotS, BG2, BG2: ToB, PST, IWD, IWD:HoW, IWD:TotL, IWD2, BGEE

DLG files contain the structure of conversations, in what is effectievly a state machine. Dialogs contains string references into the TLK file that make up the actual words of the conversation. Dialogs bear similarities to scripts; each state may have a series of trigger conditions, and effect a series of actions. If the any of the triggers for a state evaluate to false, the state is skipped and the triggers in the next state are evaluated - this occurs when entering into a dialog state, and when presenting a list of responses.

     state 0:
        trigger: NumTimesTalkedTo(0)
        Text: "Hello, sailor!"
    
    state 1:
        trigger: NumTimesTalkedToGT(5)
        Text: "Go away, already!"
    
    state 2:
        Text: "Hail and well met, yada yada yada."

Dialog always attempt to start at state 0. The first time this sample dialog is entered the trigger in state 0 is true, hence the character responds "Hello, sailor!". Subsequent times the dialog is entered the trigger in state 0 will be false, and state 1 is evaluated - this trigger also fails and so state 2 is evaluated. This state evaluates true, and get the associated message is displayed. If the dialog is initiaed five or more times, the trigger in state 1 will evaluate to true and the message associated with that state will be displayed.

In addition to the triggers outlined above, states present a list of responses (aka transitions). Each response may have a series of behaviours associated with it; the response text, a journal entry or an action.

Overall structure

Header

State table (actor responses)

Transition table (player dialog options)

State triggers (actor response conditions)

Transition triggers (player dialog option conditions)

Action table

Offset	Size (data type)	Description
0x0000	4 (char array)	Signature ('DLG ')
0x0004	4 (char array)	Version ('V1.0')
0x0008	4 (dword)	Number of states
0x000c	4 (dword)	Offset of state table from start of file
0x0010	4 (dword)	Number of transitions
0x0014	4 (dword)	Offset of transition table from start of file
0x0018	4 (dword)	Offset of state trigger table from start of file
0x001c	4 (dword)	Number of state triggers
0x0020	4 (dword)	Offset of transition trigger table from start of file
0x0024	4 (dword)	Number of transition triggers
0x0028	4 (dword)	Offset of action table from start of file
0x002c	4 (dword)	Number of actions
0x0030	4 (dword)	Flags specifying what the creature does when the dialog is interrupted by a hostile action from a EA < GOODCUTOFF creature. Bit 0: Enemy() Bit 1: EscapeArea() Bit 2: nothing (but since the action was hostile, it behaves similar to bit 0) In addition, all these bits trigger the not-pause behaviour. Hostile action is something like an effect from a spell with the hostile flag, damage effect, a simple attack or a failed pickpocket action. Note: This field does not exist in DLG files used in BG1.

Offset	Size (data type)	Description
0x0000	4 (strref)	Actor response text (i.e. what the non-player character says to the party)
0x0004	4 (dword)	Index of the first transition corresponding to this state (i.e. the index in the transition table of the first potential response the party can make in this state).
0x0008	4 (dword)	Number of transitions corresponding to this state (i.e. how many possible responses are there to this state). A consecutive range of transitions in the transition table are assigned to this state, starting from 'first', as given by the previous field, ranging up to (but not including) 'first'+'count'.
0x000c	4 (dword)	Trigger for this state (as index into the state trigger table), or 0xFFFFFFFF if no trigger is used for this state.

Offset	Size (data type)	Description
0x0000	4 (dword)	Flags: bit 0: 1=Associated text, 0=no associated text bit 1: 1=Trigger, 0=no trigger bit 2: 1=Action, 0=no action bit 3: 1=Terminates dialog, 0=has "next node" information bit 4: 1=Journal entry, 0=no journal entry bit 5: Interrupt bit 6: Add Unsolved Quest Journal entry (BG2) bit 7: Add Journal note (BG2) bit 8: Add Solved Quest Journal entry (BG2) bit 9: 1=Immediate execution of script actions, 0=Delayed execution of script actions (BGEE) bit 10: Clear actions (BGEE)
0x0004	4 (strref)	If flags bit 0 was set, this is the text associated with the transition (i.e. what the player character says)
0x0008	4 (strref)	If flags bit 4 was set, this is the text that goes into your journal after you have spoken.
0x000c	4 (dword)	If flags bit 1 was set, this is the index of this transition's trigger within the transition trigger table.
0x0010	4 (dword)	If flags bit 2 was set, this is the index of this transition's action within the action table.
0x0014	8 (resref)	If flags bit 3 was not set, this is the resource name of the DLG resource which contains the next state in the conversation.
0x001c	4 (dword)	If flags bit 3 was not set, this is the index of the next state within the DLG resource specified by the previous field. Control transfers to that state after the party has followed this transition.

This section is a series of pairs of (offset,count) of string data within the DLG file. This string data is composed of the state triggers. Note that the strings referenced by this section are NOT zero terminated. Also, the strings are typically at the very end of the file. For information on triggers, see the BG documents on writing AI scripts.

Offset	Size (data type)	Description
0x0000	4 (dword)	Offset from start of file to state trigger string.
0x0004	4 (dword)	Length in bytes of the state trigger string.

This section is a series of pairs of (offset,count) of string data within the DLG file. This string data is composed of the transition triggers. Note that the strings referenced by this section are NOT zero terminated. Also, the strings are typically at the very end of the file. For information on triggers, see the BG documents on writing AI scripts.

Offset	Size (data type)	Description
0x0000	4 (dword)	Offset from start of file to transition trigger string.
0x0004	4 (dword)	Length in bytes of the transition trigger string.

This section is a series of pairs of (offset,count) of string data within the DLG file. This string data is composed of the actions. Note that the strings referenced by this section are NOT zero terminated. Also, the strings are typically at the very end of the file. For information on actions, see the BG documents on writing AI scripts; specifically, see the section on "responses".

Offset	Size (data type)	Description
0x0000	4 (dword)	Offset from start of file to the action string.
0x0004	4 (dword)	Length in bytes of the action string.