Triggers are used to perform certain actions for specific conditions. In other pages of this site we have discussed the use of triggers in some of the most used scenarios, i.e. Setting Objectives, End Mission Triggers, Establishing Allies and working with Areas. There are many more options and interesting ways to use triggers in your missions.
NOTE: The Mission Editor Help menu has detailed information on every option.
Help / Help > Settings / Areas and Triggers / Triggers
To bring up the trigger options in the Mission Editor, click on the Settings menu and Triggers. To begin click on New on the right side of this window. The Trigger Properties window will open. There are 3 tabs: Sides, Conditions and Actions.
Sides: Check the box or boxes that will apply to the Conditions and Actions you will be selecting. You can check one box or as many as apply.