WIP
Fav if you'd like updates or if you find these blurbs useful.

There are a lot of misconceptions about Hitman 2's Ghost Mode so I've thrown together a guide for clarification and to improve matchmaking for everyone who cares to research it.

Since leaderboard place is important to me, I haven't been able to stand around and snap pictures yet.
Images are coming.

Ghost Mode Basics:
The target is always "Mark Chase" and if you miss a target, Mark Chase will continue to roam the map. Killing old targets removes a point from your score like any other non-target.
Ghost Coins are the only way to influence the opponent's world, but be careful! They also influence your own.
If your target dies after the timer reaches zero (poison, enviromental fall, choking, etc) it will cound as -1 instead of +1. The target must officially perish before the timer reaches zero (Or one, with lag.)
The bodyguard is not a witness if you KO him first. The target is allowed to see his murderer, but no witnesses may.
If you select an item from a Ghost Crate, your opponent has 30 seconds to take the same item or it disappears from their world forever. This includes the sniper rifles!
If you find a three-choice Ghost Crate with only one or two items in it, your opponent was there earlier.
Use this to get the good items early, such as pistols, fiber wire or the researcher's disguise early and deny your opponent them.

1.
Ghost Mode is PVP, even if you can't directly stab each other.
Unless it's a clear safe spot (Mark in the janitor room, for example) always be careful that your opponent isn't attempting to sabotage you into rushing or blowing your cover in a high security area.
Ghost Coins can and will be used offensively to lure attention to your take-down location.
[Janitor room img]

2.
Let some kills go.
It is far better to maintain your cover and the passive pathing for an entire section of the map than to risk it all for a point.
If the timer is ticking down, sometimes it is best to just let it go - the enemy might have fudged the attempt themselves and they could be baiting you into a terrible situation.

3.
The Opponent's world is not identical to yours.

NPCs such as The Jogging Girl and a few Casual Walkers have branching pathing and may not appear to your enemy and vice versa.
This makes the opening kill on the boardwalk a hilarious mess if you have the area swarmed by joggers but the opponent has a clear shot.
Just because he scored a point there doesn't mean it's possible or safe for you to do the same.
The Ghost Coin will sometimes trigger Mark to inspect the location instead of his bodyguard, causing a difference in game worlds that becomes obvious when your ghost opponent starts stabbing the air where the bodyguard is standing in your world.

4.
Expect Bugs.
At various times you'll see two targets appear (The first gets deactivated within 10 seconds or so of spawning, giving you a new mark on the other side of the map.)
The opponent may not see this new mark and I have no explanation for why this bug happens, but I've had enemies take down "my target" from 135m away underground. (Not sniper related. I've seen this happen multiple times with the Hospital Room / Medic Area Mark.)
[Sync Bug Img]

5.
Lethal Syringe is always an undetected kill from behind.
It's a legitimate strategy to just blitz the target while he's in public and jab.
Some players will use a ghost coin on the target in public, circle behind, jab, and let you deal with the terrible pathing and timing.
Just because the kill counts as undetected, you will still be fired upon and exposed for jabbing the target.
If your target needs to vomit, he will use the closest garbage can or toilet.

6.
Falls are not always undetected.
The Elevator Repair Girl especially will spot Mark's body before it hits the ground, voiding the kill since the body was spotted.
[Elevator Repair Girl Img]

7.
Sleeping Camera Guard is your best friend.
[Sleeping Guard Img]
In the parking garage, there is a free camera computer to hack into.
Walk behind the four guards at the entrance and simply smash the computer console in front of the sleeping guard.

8.
There are three types of ghost crates.
Clothes, Equipment and Sniper.
Sniper crates will always contain the same sniper rifles.

9.
Killing Non-Targets costs a point each. Your score cannot go beneath 0.
This means that you can effectively go wild before the first point, eliminating witnesses and clearing entire rooms before you snap Mark's neck.
It also makes coming back from a 0-1 score much easier, so long as you're not spotted.

10.
Silenced or not, the AI follows gun shots.
AI will eventually figure out where the sniper shots are coming from, even if you've gone entirely undetected.