Tri-Stat dX Invisibility rules revision
By Zegon Destructacon

Cost: 3 CP/level or 5 CP/level
Relevant Stat: Body
Required PMVs: None
Optional PMVs: Area, Targets
Progression: Linear; invisibility to +1 sense or technique each level
Reductions: Partial effectiveness
Restrictions: Time limit; invisible to certain types of characters; naked form
  only

At 3 CP/level, invisibility is basic invisibility.  It renders a character
completely invisible to one particular sense or type of detection per level,
provided the character does not move at more than half their movement rate or
directly attack anybody.  If they break either of these, the invisibility is
instantly broken and the character is no longer warded by this ability until
they re-apply it.

At 5 CP/level, invisibility is advanced invisibility.  It renders the character
completely invisible to one particular sense or type of detection per level no
matter what that character does, including attack.  Attacks still give off
indication on the location of the character, however, and do not penalize the
defendant's defense roll at all.  Once the attack happens, the invisible
character has given away their position (unless the attack was undetectable)
and can be attacked.  Attacks at invisible opponents are at a -X/2 penalty in
melee range, and a -X penalty at further than melee range.  Blind Fighting and
Blind Shooting can reduce and negate this penalty.

Sight and hearing are much more commonly used, and thus require two levels of
this attribute to be taken instead of one for them to be selected as blocked
senses.

While the character may not be detected directly by the methods invisibility
prevents, they still may be detected indirectly, such as leaving muddy tracks,
or bumping something over.