Spy checking

A BLU Pyro successfully Spy checks teammates leaving their spawn area on Harvest.

“

Hard ta stab a guy in da back when he's beatin' ya freakin' head in, huh?

Click to listen

— The Scout on anti-espionage

”

Spy checking is the common term for a thorough inquisition made by teammates in order to determine the whereabouts of enemy Spies and eliminate them. It is important to remember that Spies cannot attack while cloaked, cannot immediately attack or place Sappers after decloaking, and can effectively kill by attacking from behind. The process is somewhat complicated since disguised Spies can use the Dead Ringer to make a hasty escape when discovered.

Identifying Spies

General Strategy

Remember that players on opposite teams cannot pass through each other. Bumping into teammates that cannot be passed through indicates that that player is an enemy Spy.

Look for teammates that are behaving bizarrely. Players in unusual positions, moving in the wrong direction, deliberately avoiding contact with teammates, or hiding in corners should all be Spy checked.

Watch for teammates who are not firing their weapons or going toward resupply areas when hurt. Spies can not fire their weapon without removing their disguise, and they can not enter an enemy respawn area even when disguised.

Pay attention to the text chat. Spies will sometimes use voice commands, which will appear to all members of the opposing team as originating from the player that the Spy is disguised as. If you see voice commands originating from your name, alert teammates that the Spy is likely disguised as yourself.

Keep an eye out for telltale shrouds of smoke that are colored red or blue. When a Spy uses the Disguise Kit, it takes a second for the disguise to equip. At that time, the Spy will be shrouded with his team-colored smoke. While the smoke does not appear if the Spy is already cloaked, it will follow the Spy for a short distance if he uses it before cloaking.

Keep an eye on players who pick up health kits and the particle effects shown by the pickup. Disguised Spies will still show their team's colored particle effect when picking up health, so the contrast between their appearance and particle effect can be a dead giveaway.

If you have been killed, you can cycle through different camera angles around the map while waiting to respawn. Look out behind teammates or on open points for Spies uncloaking or disguising. Then you could Spy-Check the last known location of the Spy and the location around or near it.

Class-specific strategies

Scout

The Scout is the fastest class. Because of this, one effective strategy is to run around the map and try to bump into fellow teammates. As noted above, any teammate that cannot be passed through is an enemy Spy in disguise.

Equip the Sandman and attempt to stun any teammates suspected to be a Spy. The baseball will stun disguised Spies, but will simply pass through teammates.

Throw Mad Milk at at a teammate to Spy check them. Mad Milk will expose a disguised Spy, similar to Jarate.

Two close-range hits from the Scattergun, the Force-A-Nature, or three from the Shortstop will kill a Spy not equipped with the Dead Ringer.

Fire a single blast from the Force-A-Nature at close range. Spies will be severely hurt and sent flying by the blast.

Soldier

Fire rockets into teammates and see whether or not they are juggled by the blast. However, keep in mind that the rocket launchers have low ammo counts, so Spy checking in this manner can burn through ammo rather quickly.

The Buff Banner, Battalion's Backup and Concheror will not affect enemy Spies, so pay attention to whether or not nearby teammates begin glowing with the appropriate particle effect by the activation of either of these three weapons.

Hitting an enemy Spy with the Disciplinary Action will bestow neither you nor the Spy with a speed boost.

Pyro

The Pyro's ability to set enemies on fire with incendiary weapons is perhaps the most useful tool for detecting Spies, since only enemies can be ignited. This is the most reliable method of Spy checking teammates. The team-colored glow produced by a burning player is especially visible when surrounding a cloaked or disguised Spy. It is recommended to use only small bursts to Spy check, as a Flamethrower requires great amounts of ammunition to fire at a constant rate.

Compression blast is also useful in revealing Spies, as well as preventing them from accomplishing objectives. Teammates will not be affected by compression blast, so any teammate that can be juggled is a Spy. It is reccommended to simply ignite the Spy, as compression blast costs a considerable amount of ammo, however, this can be used to push them away from your teammates if they are in danger of being backstabbed.

If a Spy is using the Dead Ringer, they may simply die instantly from a burn. Spray fire in the vicinity to try and reignite a Spy who's feigned death.

Demoman

In close quarters, the melee weapon is probably the most effective method. In particular, the Ullapool Caber, which does not detonate on friendly players, will detonate on Spies. However, remember that the Ullapool Caber will inflict 100 self-damage upon exploding.

In narrow corridors, a set of grenades from the Grenade Launcher can serve to force a Spy to clear the area or risk being discovered by blast damage. This tactic, if the Spy's Cloak is low, can force the Spy to become visible.

Placing Stickybombs with the Stickybomb Launcher on a wide area can cause Spies to hesitate about traversing such a minefield. Teammates will simply travel over the sticky trap, while most Spies will try to navigate around it.

A Demoman using the Chargin' Targe or Splendid Screen will be stopped mid-charge when bumping into a Spy.

Heavy

Heavies can attempt to Spy check by firing their Minigun on suspicious teammates - a few seconds at close range will make quick work of an enemy Spy. However, make sure to have ammo remaining afterwards.

If a teammate eats a dropped Sandvich and was already at full health, that player is a Spy.

Because movement speed is greatly reduced, a spun-up Heavy is a tempting Backstab target. This can sometimes be used as a goad for enemy Spies to approach.

Engineer

As an Engineer, Spies are a substantial threat, as they are able to place Electro Sappers while disguised. However, this can usually be mitigated if teammates can be asked to constantly patrol the vicinity in order to discourage Spies; this can be especially helpful if Pyros can be recruited for this task. Keep an ear out for Electro Sapper notifications; if one happens while a teammate is standing near the sapped building, that teammate is probably a Spy. Still, it's advised to Spy check anybody that approaches your buildings with the Pistol or Shotgun, especially teammates that are approaching friendly buildings under suspicious circumstances. If any teammate is unable to pass through a Sentry Gun or Dispenser, that teammate is a Spy; the only exceptions are Engineers and their own buildings. Placing Sentry Guns onto an end of a long 'hall' with the Wrangler is convent, due to the minor knock-back of the bullets and the Rockets.

It is also a good idea to shoot around the immediate area with the Pistol, Shotgun or Wrangler (if equipped) to check for Spies using the Cloak and Dagger. A teammate that starts bleeding upon being hit by the Southern Hospitality is an enemy Spy. The bleeding effect will also persist when they are cloaking as well. The Short Circuit is highly unrecommended for disguised Spies can't be hurt.

Medic

As a Medic, Spies can use you to gain health while disguised. Both your Primary weapon and Melee weapon can Spycheck easily.

When using the Crusader's Crossbow, it may be hard to Spy check. The arrows stick to Spies, during Cloak and disguise, however, they also do this to teammates. However, Spies will take damage from this, instead of health.

Spies may target you while you are healing a patient. Watch your back while healing. You can also rely on your patient to spycheck, however, this could prove difficult during battle.

Spies may also simply head directly for your patient rather than yourself. Protect your patient, stop healing and quickly take out the Spy. You can also use the "Spy" voice command to alert them before they get close enough.

When using the Amputator, your taunt heals teammates in close range. Any Spies disguised will not glow the usual team-colour during this taunt.

Sniper

As a Sniper, your lack of mobility means you are an easy Spy target, especially while scoped-in. Use your SMG to shoot suspicious teammates around you, or douse them in Jarate.

The Razorback is one of the greatest Spy-stopping tools. Not only will they have to become visible from Cloak, it will also un-disguise them if they try and Backstab. They will then become stunned from the shock, making them easy to kill.

While using the Huntsman, an arrow will stick into a Spy, instead of going through them like it would toward a teammate. Use this to Spy check any teammates that are near you.

Although you can Spy check with the Huntsman, keep in mind that Crusader's Crossbow arrows will stick, no matter what team. Only you may be able to stop a Spy once you have hurt them with the Huntsman.

Sniper's Kukri can differentiate a teammate from a Spy, since they will take damage. However, the Tribalman's Shiv can do so, and with more efficiency as the player will bleed, even while cloaked.

Spy

The Spy can do a considerably good job of Spy checking. For example, your Knife, or its variants, can be used as an excellent screening tool; if you believe an ally is truly an enemy Spy in disguise, simply approach him/her from behind while your Knife is active. If you raise your Knife into the backstabbing position, you have effectively "seen through" the enemy's disguise. Spy checking someone who is actually a teammate will not yield this result.

If you suspect there is a Spy nearby, make use of the Dead Ringer. While active, the Dead Ringer can protect you from a backstab, while at the same time fooling the enemy into believing he has killed you. At this point, you can either relay to your team who the enemy Spy is disguised as, reveal his location, or dispatch him yourself.

Revealing cloaked Spies

When cloaked, Spies will "flicker" their team color upon being damaged or when bumping into members of the opposite team. Keep an eye out for such flickering figures who appear in the opposite team's color. Try to strafe while navigating corridors in case a Spy is trying to go through that same corridor.
- The Dead Ringer does not have this drawback, however it only lasts for the first 6.5 seconds of the Cloak, after which they will flicker when damaged or bumping into members of the opposite team.
- Conversely, remember that friendly Spies will always be partially visible to teammates while cloaked.

Try to listen for the sounds of decloaking. Spies' cloaks will emit unique sounds when cloaking and decloaking, such sounds indicate the presence of a Spy.

An Ammo box, Health kit, or a dropped weapon that disappears without a player walking over it, indicates that it was picked up by a cloaked Spy. (Exception: if it was a dropped weapon, it may have simply disappeared because it was not picked up in time.) Spy check the immediate area to try to reveal the Spy

In places with bodies of water, look for floating water drop particle effects. Players exiting bodies of water will be dripping with water, so any cloaked Spies that have recently entered or exited a body of water can be easily identified by this.

An automatic door that suddenly opens without any visible player being nearby indicates a cloaked Spy passing through.

In general, weapons with a wide spread such as a Shotgun or Scattergun should be used to occasionally fire into corners where Spies using the Cloak and Dagger may be hiding.

As a Scout, try to throw Mad Milk into corners and crevices. It will immediately reveal any cloaked Spies and render their Cloak useless. The Scout's speed also allows players to patrol narrow corridors and bump into Spies attempting to make their way through side paths.

As a Pyro, try to randomly puff flames while patrolling, as there is always a chance that the flames will ignite a Spy trying to pass through. Puffing into corners and crevices will also usually uncover a Spy that is using the Cloak and Dagger and is waiting to recharge it. Beware that the Dead Ringer can put out flames if they are ignited, so if an ignited Spy suddenly drops dead, spray down the area with flames to ignite him again and use the compression blast to keep him at bay until the charge on his Dead Ringer runs out.

As a Heavy, spraying an area with the Minigun where a cloaked Spy may be can prove effective in exposing (and killing) him. The Minigun has a wide spread that can reveal Spies at long range.

As an Engineer, Spies can camp by Dispensers while cloaked for an unlimited time using the Invisibility Watch or Dead Ringer, or anywhere with the Cloak and Dagger; try and check above and around friendly buildings to counter this.
- The Wrangler is also useful for spraying down areas, similar to how the Heavy can Spy check with the Minigun.
- The Southern Hospitality can be used to melee Spy check as well. The bleeding effect will render a Spy's Cloak useless, forcing him to decloak and retreat.

As a Medic, check the ÜberCharge meter upon killing an enemy Spy with the Übersaw; if the charge has not increased, the Spy is using the Dead Ringer. Be sure to keep an ear out for its distinctive decloaking noise, as Medics are high-priority targets for Spies.

As a Sniper, similar to Scouts using Mad Milk, Jarate can short out an enemy Spy's Cloak, making them easy prey. Always try to throw Jarate into corners and crevices where Spies might be hiding before beginning sniping.

As with the Southern Hospitality, the Tribalman's Shiv can render a Spy's Cloak useless. Try to hit a Spy with at least one melee hit to reduce his chances of successfully escaping. However, if he has the Dead Ringer equipped, it will remove the Shiv's bleeding effect.

Protecting the Engineer's buildings

In general, simply try to Spy check anybody approaching a friendly Engineer's buildings. Spies trying to sap a building will usually make a bee-line towards the building they want to sap, so if possible, try to body-block the Spy to prevent him from placing an Electro Sapper.

As a Pyro, use Dispensers to constantly refill the ammo of their primary weapon (Flamethrower, Backburner or Degreaser). This can be used to either create a standing firewall that Spies cannot pass through, or as periodic stops while constantly Spy checking the area.
- The Homewrecker can knock off enemy Electro Sappers with a single hit.

As a Demoman, the Stickybomb Launcher or Scottish Resistance is extremely effective at deterring enemy Spies. Simply place a few bombs around an Engineer's buildings and detonate them when the Engineer announces that his buildings are being sapped. While this may not be enough to prevent the buildings' destruction, it will at least prevent the Spy from escaping and causing more harm. It may also force the Spy to go completely around the buildings in fear of detonation by a watchful Demoman.

Similar to the Pyro, Heavies can use Dispensers to continuously refill their primary weapon's ammo, allowing players to Spy check over greater distances.

As an Engineer, always try to kill the Spy first before destroying any Electro Sappers placed on friendly buildings, as Spies will usually try to re-sap buildings immediately, or even try to kill the Engineer that is removing the Electro Sappers.
- If a Teleporter is being sapped from the Entrance, be sure not to stand on top of the Exit while destroying the Electro Sapper; some Spies will deliberately try to telefrag players on the other side. Instead, stand next to the Teleporter Exit and melee the first person that teleports through, as it will likely be the Spy. Furthermore, if the Spy does teleport through but dies on the first hit, he is likely using the Dead Ringer, so try to box him in and continue to attack to prevent him from escaping.

Identifying enemy Spies

Signs that definitely indicate an enemy Spy

Various team-colored indicators will immediately give away an enemy Spy:
- The flicker of a Cloak from being bumped or injured.
- The fading of a Cloak while cloaking or uncloaking.
- The glow from being set on fire.
- The smoke from a recent use of the Disguise Kit.
- The '+' particle emitted when picking up a source of health.

A 'teammate' that cannot pass through another 'teammate', or conversely, a 'teammate' that has been observed walking through an enemy.

A 'teammate' whose weapons are not glowing and crackling with electricity when a team-wide critboost occurs, e.g. after an Intelligence capture by your team.

A burning Pyro. Real Pyros cannot be ignited.

A 'teammate' affected by another 'teammate's' weapon that can cause knock back, such as compression blast and explosives.

Seeing the cloaked sihouette of a non-Spy, or seeing a non-Spy cloaking or uncloaking. Friendly Spies always appear to be Spies, no matter their current disguise; any other cloaked class must be a disguised enemy Spy.

A 'teammate' who can't enter a friendly resupply room.

A 'teammate' placing Electro Sappers on friendly buildings.

A friendly Engineer with the Hotrod flipped over his face, but is not holding a toolbox; this is an enemy Spy holding an Electro Sapper.

A 'teammate' standing on a friendly Sentry Gun or Dispenser, or who cannot pass through them, unless it is the Engineer who owns the building. No other team member can collide with Sentry Guns or Dispensers.

A 'teammate' with your name.

Seeing two people in the same area that have the same name. One (or both) of them is a Spy.

A non-Spy 'teammate' who picks up a health kit while at full health.

A teammate that is known to be dead or elsewhere, e.g. just respawned.

A Scout moving at the Spy's movement speed (in other words, moving slower than usual).

A Medic moving at the Spy's movement speed (very hard to notice, but if two Medics are running side by side and one is slowly falling behind, he is a Spy).

A Soldier with low health holding the Equalizer moving at normal Soldier speed.

A Soldier holding the Equalizer and being healed by a Medic.

A 'teammate' who has a name that does not correspond with his or her current class on the scoreboard. This happens when a Spy disguises as a class not currently on the team. It can also happen if the person has changed class while the Spy was disguised.

A 'teammate' that can be stunned with a friendy Sandman's baseball.

A 'teammate' who is injured by bolts from the Crusader's Crossbow instead of healed; when real teammates are hit by a crossbow bolt there is no impact sound.

A 'teammate' on an uncontested control point or near the cart on Payload maps who does not seem to be capping the point or pushing the cart (unless it is a RED player on an Attack/Defend map).

A microphone indicator that is not connected to a body on an alltalk server (cloaked Spies still display the team-colored '!' indicator).

A microphone indicator belonging to an opponent that is connected to a teammate on an alltalk server.

A 'teammate' that is using their microphone but has no corresponding microphone indicator.

A 'teammate' whose weapon sounds like the Revolver when reloading, making a single clicking sound.

A 'teammate' who is overhealed when there are no friendly Medics on the team (unless it is a friendly Pyro who has just killed an enemy with the Powerjack, a friendly Demoman who has reached the head health limit and has just killed an enemy with the Eyelander, Horseless Headless Horsemann's Headtaker, or Nessie's Nine Iron, a friendly Heavy losing his 50 additional health points 30 seconds after eating Dalokohs Bar or Fishcake, or a friendly Spy that has recently achieved a backstab with the Conniver's Kunai).

A non-Spy 'teammate' that is being ignored by an enemy Sentry Gun, even when that teammate is the closest to the Sentry Gun and thus most likely to be targeted.

A non-Spy 'teammate' being healed by an enemy Medic or Dispenser.

A 'teammate' who just picked up a med pack, and the color of the plus sign that appears over their head is the color of the enemy team.

A 'teammate' entering/exiting the enemy resupply room.

A friendly 'teammate' being affected by an enemy Medic's Amputator healing effect or, conversely, not being affected by a friendly Medic's Amputator.

The Medic's Amputator taunt buff appearing without a player, representing a cloaked enemy Spy.

A 'teammate' being soaked by friendly Jarate or Mad Milk, or not being affected by the enemy's.

A non-Spy 'teammate' not under the effects of an ÜberCharge not picking up the enemy Intelligence when touching it. Or similarly, a 'friendly' Spy who does not pick up the Intelligence while uncloaked.

A 'teammate' who is injured by the Disciplinary Action instead of given a speed boost.

A 'teammate' that makes an attack-based comment on the state of the cart when on the defensive team (or vice versa).

A 'teammate' who is wearing a hat and/or a misc item, but you cannot shuffle through their load out with the "Inspect Player" key (F by default).

A 'teammate' holding a weapon they cannot have, such as a Sniper with the Razorback holding the SMG. This can occur when the Spy tries to switch to a weapon slot containing a passive item.

A 'teammate' holding a weapon you know they are not using, such as a Sniper holding the default Sniper Rifle when you know the player always uses the Huntsman.

Signs that possibly indicate an enemy Spy

None of these indicators are conclusive proof of a Spy, but all of them would make a good time to run a Spy check:

A teammate trying to stay behind other teammates, as if trying to backstab them.

A teammate not firing at the enemy.

A Scout that doesn't double-jump.

A teammate who is in the direct firing line of an enemy but is not being fired at.

Someone who retreats backward upon seeing teammates, while still facing that teammate.

A teammate that deliberately avoids walking through other teammates in tight corridors. Many Spies will strafe walk and dodge other players to avoid bumping.

A teammate deliberately trying to avoid friendly Pyros.

A Medic who isn't healing anyone. Note that Spies are also slightly slower than Medics, so a sluggish Medic may be a Spy.

An apparently injured teammate running around the spawn area doing nothing or calling for a Medic, instead of getting health from the resupply.

Someone hiding in the shadows while in friendly territory (or where no enemies can be seen).

Someone standing still at a distance from the rest of the team. This could be a Spy trying to line up an Ambassador headshot.

A teammate calling for a Medic while at full health, while approaching friendly forces from enemy lines.

A teammate with an overheal that does not seem to be decaying or appears to be decaying very slowly; this can happen if for example a Scout disguise copies the health of a Heavy player.

Anyone hovering near Sentry Guns or Dispensers, especially if they are attempting to move behind the Engineer tending them, or are at full health.

An Engineer or Homewrecker Pyro that doesn't appear to be attacking Sappers.

Anyone running in an unexpected direction - a friendly Pyro, with full or nearly full health, running away from the enemies, is possibly a Spy.
- Anyone who comes from an unexpected place - a Sniper coming from the grate in 2Fort may be a Spy that recently uncloaked.

Someone acting inappropriately - a Pyro who stays near the Snipers, a Demoman who is near a control point and has not placed Stickybombs, etc.

A Heavy that does not spin his primary weapon when enemies appear, or is not spinning his gun when standing next to a Dispenser with the team expecting an attack.

An idle Sniper who is not zoomed in. (Spies cannot use the zoom function with their disguise.)

Someone who hesitates before running past friendly Snipers with the Razorback.

A Demoman who yells as if he is using his Chargin' Targe or Splendid Screen but doesn't move (or die). This can occur if the Spy pulls out the Dead Ringer while in such a disguise.

An Engineer that does not appear to be upgrading his buildings (or helping others upgrade theirs) when it is a good time to do so.

A teammate that is going towards the friendly Intelligence room without a reason (Usually only Spy checking Pyros, Demomen with Stickybomb Launchers, Engineers, and players who are carrying the enemy Intelligence have a reason to go to the Intelligence room).

A teammate who takes unusual routes without reason, e.g. going through the gap behind the house on Dustbowl Stage 2 after the first point has been captured may suggest a Spy.

A teammate that doesn't switch weapons much or has out a weapon that is not suitable for the situation, e.g. A Soldier with the Shovel out while trying to get past enemies.

A teammate whom you cannot perform the "Inspect Player" function on (F key by default). The only time this strategy fails is when you find a teammate who is using a completely default loadout.

Signs that indicate a teammate is not a Spy

These actions prove that a teammate is definitely not a Spy, and may also be performed to inform teammates that you are not an enemy Spy.

Can pass through teammates, as opposed to being stopped. (Beware that both teammates may be, in fact, Spies.)

Isn't soaked by friendly Jarate or Mad Milk.

Any usage of a weapon or item (shooting, swinging, eating, drinking, etc).
- Any usage of class-specific abilities, e.g. Scouts double jumping, Heavies spinning their Minigun, Snipers that are scoped in, etc.

A Scout moving at the normal Scout movement speed.

A Scout under the effects of Bonk! Atomic Punch or Crit-a-Cola.

A Sniper with the Huntsman. Spies cannot hold the Huntsman while disguised.

On fire and glowing the friendly team's color.

A friendly Spy cloaking with the friendly team's color.

A player entering a friendly resupply/respawn area.

Taunting (Disguised Spies cannot taunt).

If being fired at by enemies and is taking damage, e.g. bleeding.

Being able to pass through friendly buildings save for the Engineer who built them.

Carrying the enemy team's Intelligence. (Also, Spies cannot disguise while holding the Intelligence.)

A friendly player who is using their microphone, whose voice icon is the same color as the friendly team: A symbol appears over the player's head. In servers with sv_alltalk enabled, the symbol is tinted red or blue according to the player's true team allegiance.

Engineers carrying PDAs or toolboxes, or hauling a building.

A Demoman's eye is glowing from decapitating enemies with the Eyelander.

A Soldier with an active Buff Banner, Battalion's Backup or Concheror flag on his back.

A teammate being boosted by a friendly Buff Banner, Battalion's Backup or Concheror.

Spies with their Electro Sapper or Disguise Kit out.

Spies without a mask on (not disguised).

An Engineer Wrangling a Sentry Gun, but only if the Sentry Gun's laser sight is visibly following the Engineer's aim.

A Medic that is healing.

Any teammate dying and leaving a ragdoll of the friendly team's color.

A friendly player who does not get stunned by taunts or the Sandman.

A teammate who can be healed by the Crusader's Crossbow; when real teammates are hit with a friendly crossbow bolt, there is no impact sound of the arrow.

A friendly Soldier and a teammate receiving a speed boost when the former uses the Disciplinary Action on the latter.

A teammate who owns a headgear that has an Unusual particle effect attached to it.

A teammate whom you can perform the "Inspect Player" function on (F Key by default).

Specific anti-Spy strategies

Main article: Anti-Spy strategy

Dealing with the Dead Ringer

The Spy has the ability to feign death with one of his unlockable items, the Dead Ringer, so always be wary upon killing enemy Spies as they may still be alive elsewhere. Thus, it's best to know some of the signs that tell that the Spy may not really be dead. Spies using the Dead Ringer cannot manually Cloak, and cannot use any weapons while the Dead Ringer is out.

If an enemy dies upon the first hit while approaching friendly lines without firing his weapon, it is most probably an enemy Spy disguised as one of his teammates. Most players don't run in with such low health, and a Spy disguised as a teammate will drop a corpse of the class he was disguised as.
- Similarly, if an obvious enemy Spy disguised as a teammate approaches the front lines from the enemy's position, he is most likely using the Dead Ringer, even if he doesn't die from the first hit. Remember that the Dead Ringer cannot Cloak at will, so a Dead Ringer Spy will rely on opponents' fire activating his feign death in order to become invisible.
- In general, if a player that has been identified to be an enemy Spy seems to be approaching a teammate suicidally, he is probably trying to get damaged so that his Dead Ringer will be activated, so don't be fooled.

A Spy must take the time to pull out his Dead Ringer before it becomes active, and cannot attack while he has it out. If a Spy suddenly stops attacking before dying on the next hit, he is probably using the Dead Ringer.

The decloaking sound of the Dead Ringer is highly distinctive, but requires players to be within a certain radius to hear it. Try to patrol near rarely-traversed areas to ambush a Spy decloaking in an area that he thinks is safe.

Picking up the Spy's dropped weapon does not replenish ammo or metal. This is an easy way to double-check if a recently-killed Spy is using the Dead Ringer or not.

Spies with the Dead Ringer will not flicker when damaged or walking into enemies while cloaked for the first 6.5 seconds of the Cloak, however, they still cannot be clipped through. Being stopped while moving and not bumping into any visible objects means that a Spy whose Dead Ringer was activated is trying to pass through.

If the Spy uses his Disguise Kit shortly before being "killed," the smoke effects will follow the Spy for the time that it takes for the Disguise to be equipped. Therefore, try to track any smoke that continues to move after an enemy Spy was killed.

When playing as an Engineer, if your Sentry Gun's kill counter does not increase after killing an enemy, he is probably a Spy. Remember that it may be hard to judge if the Spy was using the Dead Ringer since Sentry Guns will generally kill their targets very quickly.

When playing as a Pyro, even when the corpse drops after being ignited, the colored team glow will follow the Spy for a second. Use this to help alert others to the Spy, and to continue to chase and/or kill them. Jarate also works in a similar way.

As a Pyro, the compression blast is the most useful tool for dealing with Dead Ringer Spies. After igniting a cloaked Dead Ringer Spy, simply push the Spy away from any ammo sources until the Cloak runs out.

Dealing with the Cloak and Dagger

The Spy's Cloak and Dagger allows him to stay cloaked indefinitely, and to hide in unconventional places while waiting for the right time to strike. An area that may seem impossible for a Spy to hide in may be sheltering a particularly cunning Spy who knows where the enemy team will not check for Spies.

In general, most Cloak and Dagger Spies will try to hide in corners in order to avoid being bumped into as they recharge their Cloak. Try to occasionally fire into corners or vantage points with wide fields of view.

One brute-force method for dealing with the Cloak and Dagger is to simply repeatedly check an area where the Spy is hiding. As the Cloak and Dagger has an extremely short charge meter, the Spy cannot make too many movements or their Cloak will run out.

Some unconventional Spies will hide out in the open rather than against walls or in corners. This allows them to maneuver easily to avoid detection, and easily avoids the most often checked areas of a map. Try to keep this in mind if a Spy is suspected to be in the area.

Dealing with Your Eternal Reward

While Spies using Your Eternal Reward cannot use their Disguise Kit at will, they make up for this by being able to quietly Backstabbing any enemies and leaving no body for their teammates to find. A Spy using Your Eternal Reward can be impossible to detect even when he is killing teammates nearby.

Because they cannot use their Disguise Kit, simply identifying the last player that the Spy Backstabbed will let teammates know which player and class may be the Spy. Note that Spies with Your Eternal Reward equipped can still change their disguise weapon.

If backstabbed by the Spy, clearly announce this to teammates, as well as the class that the Spy is now disguised as, to make sure that they know who the Spy is disguised as.

The Spy's victims make no sound and leave no body behind to discover, but the body is still visible for a short time before disappearing. If players suddenly die noiselessly in the distance, it means that the Spy is there, so make sure to warn players as needed.

When the Spy Backstabs his victim, the faint sound of the melee hit can be heard if close enough. This can serve as a key warning that a Spy might be killing teammates in the immediate vicinity.

Remember that any kills made using Your Eternal Reward will not generate kill reports for the opposite team. Pay very close attention to teammates' movements and listen for any melee hit sounds nearby.