Triggers
Shape: The shape of the trigger in 3D space (Sphere or Box). Below this option you may specify the size you want as either a radius (Sphere) or as Width, Depth, Height (Box).
Trigger Resets X Times: Specify how many times the trigger will work, where "X" is a number you input. A setting of -1 means the trigger will always work. A setting of zero means the trigger will never work (bad idea). For example: If you want to trigger a one time event, use 1.
Trigger Resets after X Seconds: Specify a delay before the trigger becomes "active" again (usable), where "X" is a number you input. Using zero here will make the trigger work as fast as possible.
Activated By:
Players Only: Only the player can set off the trigger.
All Objects: Any object passing through the trigger will set it off.
Linked Objects: Only object linked to the trigger will set it off if they pass through it.
Check Boxes
Is NPC Trigger: Allows any passing AI to activate the trigger.
Is Auto Trigger: This check box tells the trigger to activate when the level first loads.
Use Key is Required to Activate Trigger: Entering the trigger area is not enough- you must use the "Use" key to activate the trigger.
Player Weapon Activates Trigger: The trigger can be activated by a weapon projectile flying through it.
Always Show Range: Shows the range of the trigger in the editor, even if the trigger is not selected.