## Level Door Table (Class 10)

```L20``` is a table describing doors and barriers.

**Level Door Entry** (14 bytes)

    0000  [6]byte   Level object prefix
    0006  [8]bytes  Door Data


**Door Data** (8 bytes)

    0000  int16    Lock variable index
    0002  byte     Lock message
    0003  byte     Force door colour index
    0004  byte     Required access level
    0005  byte     Auto-close time; in units of approximately 0.5 seconds - common default is 0x0C
    0006  int16    Second door object index


The ```Lock variable index``` determines whether a door is locked. If the referenced boolean variable is 1, then the door won't open when used. If the door is triggered by other means, the door is unlocked and the index is reset to zero.
Using the door while being locked, the message according to ```Lock message``` is shown. The message index is into the text resource ```0x0871```, with a block offset of ```7```. (```0x00``` gives the default "The door is locked" at index ```7```).

The ```Required access level``` indicates which [access level](../content/AccessLevels.md) the hacker needs to activate
(open) the door. If zero, no special access is required. This values is ```0xFF``` for doors "locked by SHODAN level security".
Such doors have a separate trigger referring these doors.

The ```Second door object index``` refers to a second door to trigger when activating this one.
Bulkhead doors for instance reference each other this way.