2.2 - Making a door

Doors in Cave Story are made using NPCs that run an event in your text script when interacted with. A basic one can be made by placing a Null NPC and check its Interactable NPC Bit. Then, construct a TSC event like so:

#0100
<PRI<FAO0000<TRAarguments...

The <PRI command prevents the player (and anything else) from moving, and the <FAO command starts a fade out. The <TRA command is then responsible for moving the player to a new Stage, so its arguments are dependent on where you want to go. It takes the following:

<TRAnew stage ID:new event ID:starting x position:starting y position

So if you wanted to take a player to Stage #2 at position (2, 1), then it might look like

#0100
<PRI<FAO0000<TRA0002:0090:0002:0001<END

The "new Event ID" represents an event in the text script of the new stage, which is crucial: if you don't have some type of event set up in the other stage, then there will be nothing to perform the fade back in after the fade out! For this example, #0090 in stage #2 might look like:

#0090
<MNA<CMU0008<FAI0000<END

Here, <MNA displays the new stage name, and <CMU sets the music track to be played. Then <FAI fades the game back in. Once you have your events set up, you can set the event ID on your NPC to e.g. 100 to have your script fire on interaction.

If you want to make a closed door that visibly opens when interacted with, you can use a Door NPC rather than a Null NPC. Then, you can use the <DNP and <SOU commands in your event:

#0100
<PRI<SOU0011<DNP0100<FAO000<TRA0002:0090:0002:0001<END

The <SOU command plays sound 11, which the sound of opening a door.

The <DNP command deletes NPCs attached to the specified event, thus removing the door when interacted with.