Three Trigger Logic is basically having multiple triggers(Unit Triggers) required to say open something or make the boss vulnerable to your attacks.
In this guide, I will be using a boss battle as an example. He has two stages:
1)Invulnerable/Not Targetable, but has three switches that will allow you to begin your onslaught.
2)Vulnerable/Targetable, can be killed
(Note: I tested and seem to have found a bug because the Invincible field doesn't seem to work, but it good to have both on anyways)
First things first, here is everything you will need:
A map of course
The Boss, which is a Monster Building Block
The Three Triggers, which are unit triggers with a certain model selected(in this example, vases)
A Counter, which is in Logic
and a Logic Group, which is also in logic.
Here is how I set my map up, you don't need to be so elaborate in your test:
First and obviously, create a basic map to place stuff on.
1.) Now Create your Monster(Right-Click on layout tab>>Building Blocks>>Monster), be sure to set him to Invincible True, and Targetable False.
2.) Now place your three unit triggers(Building Blocks>>Unit Trigger) somewhere on the map, select a model for them in the properties, and leave everything else alone.
3.) Now you have everything you need for player interaction. Its time to create the stuff that happens in the background.
4.) Create a Counter(Logic>>Counter) if you haven't already; in the Properties Change the EQUALS VALUE field to 3. The counter is the second most important piece in this guide.
5.) Now it's time to connect everything, Create a Logic Group(Logic>>Logic Group); click the little hammer/wrench that appears next to the "-"(Collapse All Groups).
6.) Drag the Monster, three triggers, and counter from the layout tab to the logic editor window.
7.) This part is what makes this thing work. In the logic editor make it look like:
Greens are outputs, and blues are inputs.
Basically this Logic will add '1' for each Unit Trigger you activate(click), once it reaches 3 the counter will send it's activated signal to the Monster who at that time will become targetable and vulnerable.
Hope this enlightened people a little on basic use of the Logic Group. If you need clarification, feel free to ask.
If you want more on Logic Groups All three of the Runic Video Tutorials are about its uses.
Enjoy the editor.