Written By: Dragoon Falcon

The purpose of this tutorial is to show how to track the movements (in either direction) of characters through a one-square-wide passage.

This effect requires a minimum of two events, and at least one event for every 2.5 characters.

Note:
This tutorial assumes that every player character is unique.
For the remainder of this tutorial, I'll refer to the place where the units will enter as the "left" and the direction where they will exit as the "right".

For simplicity, let's deal with the case where you only need to track the movement of one unit. Call it Bob.
You need two "other"-class events.
|__|
??
|--|

(The events are here denoted by the question marks.)
The left event should have one "subevent" (you know, one of those five things at the bottom) activated by the condition "Bob passes by". I like to call this subevent "Bob Left". That subevent should turn off a switch (which I will call "Bob is to the right").
The right event should also have one "subevent" activated by Bob passing by. Call this subevent "Bob Right". This one should turn on the switch "Bob is to the right."

Now, if this passage is the only way to get from the left to the right, any event can can tell at any time whether Bob is on the left or the right of the passage. Nice, huh?

In the case of, say, seven units (A through G), there should be three events:
|___|
123
|---|

Event one should have A Left through E Left. Event two should have F and G Left, as well as A through C Right. Event three should have D-G Right.

For ten units, for example (A through J), you'll need four events:
|____|
1234
|----|

Event 1 should have A-E Left. 2 should have F-J Left. 3 should have A-E Right. 4 should have F-J Right.

(There are other possible configurations, but I wanted to make sure to show some that worked).

Finally, in my game I use this to tell when my party of fleeing characters have all passed a certain point. At the instant they're all past that point, the battle ends. If you want some event to execute once all the units have gone through the valve, place a statement in all the "Right" subevents that checks if all the "someone is to the right" switches are on, and then if they are, carries something out.

Hopefully it shouldn't be too hard for you to discern some other uses and implications for this system. I hope you have a good time using Sim RPG Maker 95!