The question now is whether or not this guide as written here can be made remotely reachable by actual playersA guide written by Nic, made for the joe.to TF2 servers, where FF happens to be on, and lessons on spy-checking carry elsewhere.
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How do you figure out who's spy and who's not, when friendly fire makes things complicated?
1) Caught in the act
This one is trivial: You see a plain enemy spy undisguised, maybe starting to disguise into one of your teammates,
or an engineer building is getting sapped right before your eyes, or a teammate is making a strange beeline to another teammate's back.
Apply lead.
2) The spy is on fire.
Fortunately, even with FF on, Pyro's flamethrower is teamsafe. This is good.
The flare, however, is NOT teamsafe. Be careful.
Enemy spies will ignite in the wrong color -- REDs burst into regular flames, while BLUs burst into a flame with bluish coloring near their feet.
If a BLU teammate burns like a RED or vice versa, go slaying.
3) Solidity
Enemies are solid to you, while teammates are not. If you can't walk through a teammate, he's a spy.
If a non-engy teammate can jump on top of your team's sentries/dispensers, he's a spy.
If an engy is on top of a different engy's buildings, he's a spy.
4) Flaws in invisibility
Friendly spies can be slightly seen when invisible, with the appropriate color of their team.
Enemy spies shimmer the wrong color when exposed while invisible under the regular cloak watch.
This shimmering happens on damage, on bumping, and right before he decloaks (into what appears to be a teammate).
Cloak and Dagger spies also shimmer when their cloak runs out. They'll immediately be invisible again when they stop.
Dead Ringer spies do NOT shimmer when hit after their cloak is triggered.
However, their decloaking noise is dead obvious.
Spies under the effect of Jarate is permanently shimmering.
If allchat is on, speech bubbles will appear if the spy uses voice chat while cloaked.
If the "!" in the bubble is in the wrong color (and you can't see anything below the bubble), fire toward the general area of the bubble.
Dispensers will heal cloaked, disguised spies. If you see a dispenser healing thin air, fire toward the general area.
Cloaked spies can still pick up health and ammo. If you see health/ammo disappearing out of thin air, there's a spy out there.
5) Names
A disguised spy of a certain class will be randomly named after someone on your team on the same class and have the same health, if possible.
If nobody on your team is of that class, that spy will have a random name.
If you somehow meet a clone of yourself, kill your evil twin.
If you meet a teammate that just died, kill the ghost.
If you meet two teammates with the same name, apply another method fast or pray that the teammate notices fast.
Be aware of what's going on. If you see a teammate that shouldn't be where he is given what you have seen, it's a good idea to investigate.
6) General flaws in disguises
Currently, a spy disguising as a spy might end up with "Disguised as Enemy" with no class indication. This is an enemy spy.
A disguised spy cannot reload. If someone is reloading, he's a teammate.
A disguised spy will do a special sapping animation while placing a sapper.
A spy might pick to disguise as a class that's not played by anyone in your team. Know your team composition.
If a teammate seems a tad too reluctant to fire his weapon, he's probably a spy.
On the flipside, if a teammate fires his weapon, he's not a spy.
Pay attention as teammates go onto a control point. A spy won't add to the person-counter while capturing a point.
7) Specific flaws in disguises
As a scout, the spy runs a bit slower and cannot double-jump -- although double-check if the scout has a Sandman.
As a soldier, nothing particularly telling. Soldiers are slow, and so aren't popular -- they're a common medic target though.
As a pyro, nothing particularly telling, but he'd never flamecheck. Additionally, a good medic target.
As a demoman, nothing particularly telling, but most demomen are aggressive and tend to spam explosives.
As a heavy, nothing particularly telling, but given heavy's slow speed, it's uncommon to see spies disguised as them -- but then, medics do like
heavies. Also, note that spies cannot pre-spin their minigun.
As an engineer, nothing particularly telling again, but this is a common disguise.
As a medic, the spy is not busy healing the shit out of everyone.
As a sniper, the spy never holds the rifle to his eye/ready an arrow like other snipers would.
As a friendly spy, the spy might be disguised, but not disguised as a particular enemy in the "Disguised as" popup.
8) Freaky behavior
Let's list common freaky behaviors that you'll see coming from spies:
-The wrong class at the wrong place (i.e., a sniper heading way back to intel)
-Hiding in corners where you usually won't see them, but in clear view of enemies.
-Backpedalling upon seeing you in a tight corridor (huuuge giveaway)
-Constant avoidance of other teammates
-A teammate making a beeline for someone's back/a random engy structure, generally in an oddly confident straight line.
These kinds of behaviors doesn't always mean that the teammate is a spy, but most of the time, he is.
If you don't feel confident enough that the person is a spy, just apply another method to check for spies.
9) One more thing
If someone screams out for medic way, way too often, smack him.
This is the sign of a novice spy or someone that just needs smacking (although if he's actually a teammate, you might scolded).
10) One last thing
If you see a teammate, it's generally a good idea to show that you're not a spy.
Switch your weapons a few times (unless you're already on secondary/etc) or fire a stray shot somewhere.
As a scout, double jumping is an option.
As a demoman, do note that it's usually tough to figure out if you're holding your primary or secondary weapon. The bottle works.
*) Notable exceptions
As a last-ditch effort, note that enemy spies don't bleed if FF is on.
Given no other options, poke a teammate (grazing shotgun shot at a distance, pistol/syringe fire, etc).
If his health goes down/you see him bleed, it's a teammate.
If you're a medic using the Blutsauger, do a poke and see if a +3 health text pops up. If it does, the enemy is a spy.
You can also use the ubersaw (+25% charge if the guy you're poking is a spy), but that's more of a means of spy disposal, not checking.
*) Special things
Dead Ringer spies currently take a little extra effort to kill -- if they are not cloaked and are holding up the watch,
any damage he takes is reduced by 90+% and his corpse is dropped. There won't be any good indication as to whether or not who
you killed is an impostor, but it's a good idea to fire at least one more shot.
If the spy is constantly decloaking to make himself a damage sponge, you'll be able to tell due to the ridiculously obvious noise.
Keep tracking him.
You probably won't be able to kill him using normal-speed weapon due to the damage absorption (i.e. with a shotgun, rocket, etc),
so it's a good idea to pull out your faster weapons or bring a pyro along.
Don't stand on friendly teleporter exits. Spies can take friendly teleporters, and yes, they will telefrag you.
*) General tips
If a spy is in a crowd of teammates, it might be a good idea to pull out a more surgical weapon.
Rockets, grenades, and stickies are usually not a good idea while the spy is next to your medic.
Alert others. If you spot a spy, tell everyone (also, do tell where the spy is).
If you see voice macros (Medic! Help! etc) coming from an impostor, tell everyone.
Think like a spy. If you feel that you'd make a good, easy target for a spy at the moment, make yourself a harder target.
Remember all the good hidey spots for spies. If you have enough health and spare time, check hiding spots.
Be environmentally aware. If you see/hear a backstab kill (...or three) (in some servers people won't turn around even at five),
it's a good idea to look around.
Listen to engineers. They will automatically scream out if something of theirs is being sapped.
You won't be able to tell between teleporter entrances and exits being sapped, but if anything is getting sapped, you should be wary.
Again, shooting teammates and checking for bleeding should only be a last-resort thing.
Look around. Often. Standing still is also not a good idea.
Play often. Spy-spotting gets natural over time.
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Most suggestions are welcome. If I missed something, tell me, won't you?
who "whine that it's hard to spot spies with FF on" in the server (without asking them to go to the website too much).
(actually never mind, I'll start nagging them more)
I probably won't post this where it'd actually be read, like in the Steam forums, simply because of how FF-oriented this guide is -- but in retrospect,
FF doesn't actually do much to actual spy-spotting.
(made 5th jan 08)
(edit 6th jan 08 - additions, modified Freaky Behaviors)
(edit 7th jan 08 - teleports, one more freaky behavior)
(edit 8th jan 08 - reloading, think like a spy)
(edit 10th jan 08 - capture points, heavies, +tip)
(edit 5th may 08 - teletrails patched)
(edit 27th jun 08 - no unlockable weapon while disguised)
(edit 5th aug 08 - blutsauger and flare gun)
(edit 24th may 09 - big spy update)