Baldur's Gate Scripts

They have one fun feature:
https://www.pocketplane.net/tutorials/simscript.html
Shouts are almost a form of communication between scripts. Shouts are effectively numbers, but liked to an IDS file for better identification.
So, in one script, if you use:
IF
// Triggers
THEN
RESPONSE #100
Shout(1001)
END
The shout 1001 will be used. With an IDS entry, this can of course be changed to something like MY_SHOUT.

In a completely separate script, a shout can then be picked up:
IF
Heard([ANYONE],1001)
THEN
RESPONSE #100
// Actions
END
However, note that a shout can only be 'heard' within the same script cycle as it occurs; as such, the two scripts must also be running simultaneously.

This allows communication between different creatures. Shouts are intended to be realistic, and the range of a Shout() action is slightly greater than visual range. A GlobalShout() action, however, can be Heard() throughout the entire area.

Later Bioware dropped this reactive programming in favor of a C++ like language.