The Event_Lightning - by Steve Rescoe

The QuakeLab - http://www.in2nett.com/stevefu/QuakeLab

        TEXTURES:

        Up to you.

        ENTITIES:

        func_door, event_lightning, func_button, monster_boss, item_sigil

        WHAT TO DO:

        This is not a very well understood phenomena. However, here is
        what will work:

        Make two func_door entities out of 'tower' shaped brushes which
        will form the two vertical "conducting rods". Set them apart
        from each other and set their 'angle' fields to -2 (down.) Give
        them different targetnames. Set their 'target' fields to read
        'lightning'. 

        Next, make two func_button entities that correspondingly target
        the func_doors.

        Next, make an event_lightning entity and give it a targetname.
        Make a third func_button which targets the event_lightning.

        That's it.

        NOTES/COMMENTS:

        When running LIGHT, you will receive a message telling you that
        the two func_doors with the 'target' fields of 'lightning' have
        no corresponding targets. This, from what has been observed so
        far, doesn't have an adverse effect on the level. However, you
        can make a dummy entity which the doors can target without causing
        any problems. A wall torch or a func_wall entity would do just
        fine to prevent those messages from showing up in LIGHT.

        You can set a single button to activate both func_doors if you wish.
        You can also alter the wait, sounds, and speed fields for the
        func_buttons and func_doors.

        The func_doors can be set at non-coplanar locations (i.e. you can
        make the lightning fire diagonally from one func_door to the
        other.

        The lightning does not damage anything except for Cthon.

        You might try further experimenting by setting up more than two
        func_doors with lightning targets. Perhaps three bolts might fire?