When a laser tag phaser fires a shot what you see is a laser
beam. The laser beam is for affect only. What scores the actual hit
or tag depends on the system in which you are playing )typically
it's an IR or infrared signal), much like the kind used in your
television remote control.
While you are firing an actual laser in laser tag, the actual
entity tagging an opponent's pack is typically an IR signal.
Agree" sales(@)kitelaser.com
The above answer is fairly accurate, however to be more
specific, it's not Infra-Red signals that determine whether a tag
is scored as much as it is FM signals, much like the frequencies
used in radio.
Disagree:
I know for a fact that pure laser tag, without IR or FM first
existed commercially in 1986 and used solar cells as receivers. Why
it never really took off until recently I do not know.
Laser Runner claims to be the only existing pure laser tag
technology:
http://www.lazerrunner.com/mod.php?mod=userpage&menu=13&page_id=30