Note: for those who prefers not to see anime illustrations when reading the guide, I have organized the guide so that the texts are clearly separated into sections that can be read without having the anime illustrations take up too much space on the screen.

I can understand that people prefer not to have anime stuff involved, I can also understand that people value their feelings enough to turn them into public opinions when involving certain things like anime. I don't mind if people openly despise and comment their hate, it is only fair because I also implemented it into the guide without much consideration for other people's opinion.

I'll let you do what you wish since I'm also doing the same.

However I will not remove the anime illustrations. They may be bad in terms of tastes or preferences, but I do not think that they are bad enough to affect people physically with conditions that are more severe than merely cringing, wincing or recoiling at the sight of anime content. Thus I deem the presence of anime illustrations in the guide to be harmless and negative reactions towards them to be normal.

If you are to rate or criticize the guide, please do so objectively. If the information within the guide is beneficial enough to be helpful to you then the guide is to be considered positive enough to be satisfactory, the guide and all information contained within should not be judged with bias influenced by your hate for the decoration pieces that are irrelevant to the content.

Note: I've hit the character limit for the guide's content so I can't post links to the art sources.

• Recycling old magazines: if it is a risk you think you can take, try to shoot until your mag is empty. When you unload more than half of your magazine's capacity away, it is natural to reload back up to full in order to be ready for the next engagement. But always remember that the old magazines will be used again later once you've cycled through all the new mags, you don't want to load in an old magazine with only a few rounds left!
  
  
• Ammo check/chamber check: If you have a weapon mod that include a visually different reloading animations for when the weapon is empty and when the magazine still has rounds left, you are able to reload and quickly cancel by switching your weapons in order to determine if your gun still has rounds left in it or not. Alternatively, some weapon mods has a feature that shows the charging handle/bolt locking back once the gun is empty, such as the Kel-Tec RFB (old and unsupported now). If your weapon has neither of those then you can look at the magazine model when reloading, in the case that your weapon mod has modelled bullets in the magazine when not empty and empty out when there are none left.
  
  
  
• Magazine check: quickly swap weapons to check the hud at the bottom right corner of the screen for how many mags you have left. The magazine counter number will be for the weapon you're switching to. Alternatively you can press the respective number key for the gun you're holding, 1 for primary and 2 for secondary and the mag count will be there without swapping weapons.
  
  
• Sprinting reload: nearing the end of most fully empty reload animations you are able to start sprinting without cancelling the reload and having to do the entire thing again. The timing has to be precisely near the end, usually around the part where your hand touches the charging handle and is about to charge it or when you press the button to release the bolt locking back in its place (does not work with weapons that reloads rounds/shells individually). But always remember! This is mainly a movement/traversal trick, not a combat trick. If you run dry while engaging, cover first then reload later. You are not supposed to reload first then slowly walk into cover, if a reload takes 4 seconds you still have 3 seconds for you to die first before you can use the 4th second to sprint away.
  
  
• Creating a slightly safer area with smoke grenades: enemies closing in from multiple directions? throw a smoke grenade into the corner and get the jump on them (provided they don't blind fire into the whole thing). Everyone is more confident in pulling the trigger if they can directly see the target they're aiming at, but if they have to put in more effort in finding you then that gives you more time to work. If you're outside the smoke and the enemy is inside then shining your flashlight into it will reveal silhouettes of the people inside, unless they're in the deep end or the opposite side of the cloud from where you're shining the light from. If you're inside the smoke, avoid the middle of the cloud (where the grenade is) as that will blind you completely. As you move further away from the center of the cloud it will be easier for you to see but it's also easier for you to be seen as well.
  
  
• Grenades usage: left mouse click pull the pin without keeping the spoon and throw, holding it down allow you to cook it. Middle mouse button does an underhand toss, can be used to roll the grenade foward but only a little bit. Right mouse click pull the pin while keeping the spoon, can be held indefinitely. If you keep the spoon (not using the left click) you can cancel the throw as long as you don't release the grenade by switching your weapon.
  
  
• Other grenade information: frags have 4s fuses, smoke has 5s, AN-M14 has 1.8s. Both frags have a 5m kill radius, smoke lasts about 24-25s, the Insurgency Wikia shows that the AN-M14 last around the same amount of time, presumably the molotov as well. Both the molotov and the AN-M14 does 100 DMG on detonation, the AN-M14 does 76 DMG per 0.38s while the molotov does 18 DMG per 0.44s (information is possibly outdated).
  
  More info here: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1106790511
  
  
  
• Readying your equipment: every time you spawn in you will ready your weapon by doing a slightly long but cool animation, this applies for primary, secondary and launchers, and only for the first time you equip that weapon. This will be done only when you pull out your weapon while in the re-supply zone indicated by the supply icon on the screen, moreover this area can be seen as a blue zone on the map with the symbol of the team you belong to. It is recommended you ready all your weapons to avoid doing the long animation in a situation where you capture a point and being in the re-supply zone dictates you take a few seconds longer for you to pull your sidearm out. Be careful, be vigilant, be ready.
  
  
• Quick resupply instead of reloading: bind the resupply key into a key you're comfortable with using console commands and you can press that button to instantly resupply, it's the difference between using 4 seconds to swap mags and fully reload and using only a few seconds to just pull out and ready a new weapon. To bind a key use the console command menu and type in bind "v" "inventory_resupply" (in this case I use V but choose a key you're comfortable with). For me I am able to bind it once with console command and I never have to bind it again, but if for whatever reason it only applies only for the current session and not the next time you start up the game you might have to edit the autoexec.cfg
  
  
• How to night maps: you don't. You just wish for it to be over quickly enough you don't have to suffer for long. But in all seriousness my advice is stick with your teammates, multiple pair of eyes in the dark will help you spot enemies more consistently if you don't trust your own ability to see. Limit flashlight usage only for when engaging and not traversing the map, you can use NVG for moving around in the dark if you know there's quite some distance to get to the fight and if you absolutely can't see where you're going. There is an approximately 2-3 seconds of blindness for your eyes to get accsutomed to the change in lighting, you need to be safe and ready before you put in on and move out. The blind time will vary based on if you're looking at something bright or not; if you're in a well lit room your eyes can take up to 5-6 seconds to get used to the NVG, if you're out in the dark it will only take a few seconds.
  
  
• Increasing visibility with flashlights: the usage of flashlights is not only reserved for dark areas. When there are thick layering effects namely fire from incendiary, molotov and map aesthetics (ie. fire pits or flaming wreckage) and smoke generated from fire or smoke grenades, you can shine your flashlight through them to highlight the silhouettes of whoever's behind those layers obstructing your view. This can be further exploited with a player model that has poor shading properties, making the silhouttes appear more prominently. For example the heavy bucket helmets for the bots; they appear dark black in color (highly visible in smoke). My guess is that this is because the object is in a smoked area where no environmental light sources can reach it, when a flashlight shines on it the object is shown but without any of its color and texture being lit up like the object doesn't register the flashlight as a valid light source. (Speculation is most likely BS)

Detailed statistics on damage can be found here: http://jballou.com/insurgency/stats.php
Just change from doi to insurgency and click on parse.

You get 100 HP per life and resupplying restores you back up to full. It's a good idea to resupply at least once per objective in that regard so that you can take the maximum amount of damage for each engagement, this helps if you want to run through incendiary grenades or molotovs without dying on the way through.

Having maximum HP helps with chip damage like long distance grenade explosions, bullets that penetrated a wall to reach you, damage over time from fires and stray shots from far enough away to have damage fall off from the distance.

• Crossing an area under heavy gunfire: look both ways before crossing a shoot out between two sides. Imagine the bullets are cars on the street, but in this case they're super sonic and hurt a lot, if you try to cross an area while people are shooting at each other you are essentially trying to run across a highway. Be it a room or a field, you should always look to go around the back of your teammates even if you have to back track from your current position. If you absolutely have to cross in front, possibly due to your teammate being next to a wall that you can't go around, prone and crawl.
  
  
• Crossing in front of a teammate aiming and covering an area: if they are firing wait until they stop firing having either killed the enemy that is present or having to reload and then cross. Keep the cross as short as possible, sprint through and try not to obstruct your teammate for too long. Cross in front when the teammate is done firing and not when they're about to fire.
  
  
• Keeping your distance: from the cover you're currently using and your teammates. Being too close to your cover means that you have to turn more before you can move foward back into cover cover, or if you decide to strafe sideways into cover while shooting your gun, it will be too close to your cover and gun collision will force you to lower your weapon which prevents you from shooting effectively. Avoid being near teammates when crossing open areas or when not in full cover, any enemy who's trying to hit your teammate can hit you if you're too close to them and it's unfortunate if you catch stray bullets that are not meant for you.
  
  
• Don't move without a purpose: this happens a lot to me and others that I've seen, most often when we're chilling at objectives people just wander around without doing anything in particular. It's not neccessarily a bad thing when there are no enemies, you're free to do whatever; explore the area and try to be more familiar with it or looking down to find grenades you can use etc. But when the enemy is about to attack your position, stop what you're doing and focus on defending. Don't wander around and block paths, passages, doorways or be a nuisance to the team if you're not moving with a purpose in mind. You can patrol a little bit to check if a teammate has died while defending and an area is left uncovered then you can refill that spot and plug up the hole the enemy can leak in from.
  
  
• Positioning: stick to walls and corners to minimize your operational angle. The middle and open areas are for crossing from one side to another, don't stay for too long.
  
  
  
  
• Cover Usage: all cover are more or less obstructional only, which means only for breaking line of sight. For cover types there are the common 2 sided covers (back and forth), the corner-like L shape cover (not just front but also left or right) and the super rare U shape cover (such as foxholes or sandbags). Use each cover type effectively, place yourself and position your enemy in the ideal direction based off of the cover, for example if you are behind cover looking forward and there's no enemy there but someone shoots you from behind just run forward past the cover and switch to the otherside.
  
  
• Narrow Corridors: If there's a corridor that can only fit one or two people at most width-wise then go in one at a time, not all together. If the teammate in front fails to kill the enemy they can and will shoot through the body and mow down everybody in the corridor behind that teammate. If you're behind the person in front, you can't shoot past them anyway so let them clear the way before you follow them into the line of fire. Narrow funnels or choke points like those are ideal camping spots for killing a lot of people who are trying to move through quickly so be careful.
  
  
• Situational Awareness: you cannot be expected to maintain SitAwareness across your entire operational angle and at all time unless you're in a dead end alley or hiding in a room covering the one and only entrance you have. The moment you engage the enemy, your focus will shift only to your enemy in front and not anywhere else. But even so there will be moments where you break off from firing and get back into cover, that will be your chance to check your surroundings. I've seen a lot of people getting shot up the bum because they take the safety of their far away or hidden position for granted and never bothered checking left, right or behind when they're not busy shooting. You don't have to check constantly but be sure to look around consistently and occasionally whenever you're not shooting, just think of it as finding things to shoot.
  
  
• Handling Threats From Multiple Directions: use cover manipulation like previously mentioned and 'dance' around the cover clearing each direction seperately, the ideal number of directions for this trick is 3. 1 is normal and 2 you can switch your aim back and forth well enough. If you have a 2 sided cover then try your best to round up two directions that are close together and place the cover in between you and those directions while engaging the 1 direction you can't have the cover for. If you have a L shape cover then do the same but it'll be easier to place the cover in those 2 directions. In practice it'll be like this; let's say your 3 directions are front, back left and back right. Walk past the cover and place it behind you while shooting forward, once that direction is taken cared off you can walk right towards the direction of the back right enemy and clear them out, once no one is in that direction you can either continue forward around the cover you're 'dancing' around or turn around to check behind you while circling back to shoot the back left direction from the other side. Basic principle is: engage 1 direction while trying not to get shot from the rest

• Advantages: less concern for friendly fire (as long as you know they're in a different area). You are your only limitation, there will no one to impose restrictions on you allowing you to move and act freely, weapons free. You advance at your own pace, kill as many as you want, go to the objective with the route you have in mind.
  
  
• Disadvantages: increased requirement for independency, spatial awareness, speed, reflex, reaction time etc. When you inevitably rejoin with the team you will have to turn off your 'shoot to kill, free fire zone' mode, lest your teammate(s) suddenly pop out from around the next corner and your reflex take over.
  
  
• Tips: good positioning can help you out a lot, if you don't want to be aware of all 360 degrees around you then place yourself next to a wall and then you'll only have to worry about the 180 degree. Be aware of who's gonna come around the corner of the wall you're next to though. Having only a 180 degree arc for you to look at is a big difference between checking behind you as well and only having to check your left and right. Don't stay in one place for too long, or if you want to then keep roaming around that immediate area.
  
  

• Advantages: less concern for other zones or angles of approach from the enemy, your team should cover and clear their own respective areas leaving you to focus on your own. With multiple team members working, covering, clearing the immediate area around your own position, you are relatively safer than being alone and that allows you more time for actions such as reloading. I usually imagine that I have a strict time limit when performing certain actions and if I take too long I will die, having teammates greatly increases that time limit until you need to be ready, of course you should strive to perform your best without relying on your team too much. What you receive from your teammates, you should be able to return to them the same benefits.
  
  
• Disadvantages: increased requirement for cooperation, possible bad teammates, higher chance for friendly fire and trigger discipline is recommended. If your teammates requires a higher level of performance from you for whatever reason, you may need to perform similarly to how you would while soloing while under restrictions from your teammates which can be tricky.
  
  
• Tips: use the map to determine which direction your teammates are covering and fill in the gap of the team. If every possible direction is covered you can patrol from place to place and be ready to provide support to whichever direction is under attack. Similary for offence, if most of your team are converging and moving into one area then look out for possible flankers from the side or behind. If you are behind the group let your frontline teammates handle the front, don't try to shoot past your teammate who are in front of you. If you want to go but they're too slow, go to the side and go around them. Deciding whether to stick with your team or go hunt alone is entirely up to you, do what you feel is best and comfortable for you in order for you to perform well and help the team.
  
  
• Other tips: if an enemy sneaks in between you and another team member or if a teammate steps in between you and the enemy while you two are staring at gunpoint; feel free to shoot the enemy, you don't have to wait for the enemy to open fire first to have a 'self-defense' reasoning when you accidentally kill your teammate. If you are accurate enough to aim around the teammate's hit box then try to, if not then just aim for the enemy and shoot until the enemy drops. If your unfortunate teammate understand what had to be done, they shouldn't be angry at you and hopefully they will realize they shouldn't try to step in front again a second time. But on the battlefield there are not many second chances, everytime you die there's a chance the rest of your team won't make it to the next objective and lose the round, don't take any unnecessary risks. One person dying while killing an enemy can even be considered by some as canceling each other out, not to mention if you die then and there you won't have be able to proceed and kill even more enemies for the team. Two people dying cause of one enemy exploiting a hostage situation dilemma is a just a needless loss of two lives. Sometimes it's better not to ask for permission, but rather, forgiveness.
  
  

How fast your team progresses depends on the effectiveness of your team and how much resistance the enemy is putting up, it's okay to slow it down and make sure you don't make unnecessary mistakes and die needlessly as long as time is not a concern.

• Be aware of your role in the team, if there is an open gap or spot for you to take then make sure you cover it otherwise the entire team is at risk.
  
  
• The unit composition is generally frontliners up at the front, flankers on the side and reserves at the back.
  
  
• When the people at the front dies, the reserve at the back has to step up and maintain the frontline and prevent it from collapsing. If the frontline collapses and the enemy moves in and drive a wedge right into the middle of your team, the team may have to fall back and regroup or else certain team members can be seperated and isolated people are easy to pick off.
  
  
• Frontliners are responsible for engaging the enemy and moving in to take over the enemy's position when you are able, the rest of the team should keep up at your pace but not when you rush in without establishing a solid frontline and enemies roam freely around the area.
  
  
• Flankers/Anti-Flankers on the sides are going to be seperated from the team and can be easily surrounded if the middle area's frontline has collapsed and the enemy start roaming all over. Flankers are mainly for infiltrating the enemy's frontline and wipe them out from where they are unprepared, in the case that the team's frontline are slowed down by heavy resistance and keeping the enemy busy.
  
  
• Reserves also have to be careful about enemies coming from behind and start biting the team's butt hole; more specifically you. Moreover you will have to be aware of the flankers' status, if they go down then the sides are exposed and you may have to fill in that gap as well as the frontline.

The strategy slightly changes depending on the location you are defending. Consider factors such as is it indoors, outdoors or both? Is it a large area or just a bunch of rooms? How many possible entry points, entrances, angles of approach? How many windows, holes, or shooting spots are there for the team? Which direction is the enemy coming from, is it multiple directions at once? etc.

• Maintain the perimeter: keep the enemy at bay and prevent them from storming in, continue killing as many as you can as the enemy approaches. You will be not have any breathing room until you kill enough to create your own.
  
  
• Take up a position and cover an area: just pick a spot and kill any enemies that moves in on you.
  
  
• Adjust according to the enemy: if no one comes from one side, but there's a super intense shoot out going on elsewhere then adjust accordingly.
  
  
• Figuring out what to do: You may have to refill the frontline by taking up the spot where your teammates died trying to hold off the enemy, now it's your turn to hold them off. If the frontline is full and there are no spots for you then be mindful of other areas that the team can be flanked from, all the while being aware of the frontline's status and see if they need support from the reserves.
  
  
• Don't do anything counter productive: it's better to do nothing if you can't be productive than to be counter productive. Don't move without a purpose, feel free to sit down and think clearly on what you have to do before doing it (if you have time to do so). If there is absolutely nothing for you to do then you can hang back for a bit, just sit back and be ready to refill the front. You can stack up against the same cover as your teammates at the frontline, but keep in mind that while you're waiting to take up your teammate's position you are all vulnerable to RPGs and grenades when you are close together. Being part of the reserves at the back can reduce the risk of losing too many team members from explosions.

• Description: this style is essentially for people who likes the adrenaline rush or like being a speed freak. This is my favourite and main playstyle due to its fast pace. Fast assault, full auto, quick kills in rapid succession, moving and clearing areas quickly etc. It can be summed up to the faster you are, the longer you live. (When performing certain actions, this doesn't mean you rush off and hurry to your death.)
  
  
• Playstyle info: engagement range is as close as that of urban areas like Tell, Contact, District, Revolt etc. Weapons are fully automatic weapons with 30 or more rounds per magazine, relying on quick target acquisition and trigger pull to take down enemies before they return fire and kill you.
  
  
• Specialization: breaching and clearing as a point man, because you're quicker than your teammates with long range weapons or those with slower speed you can move in and clear out small spaces faster and without needing to risk the lives of your teammates if you can handle it for them.
  
  
• Unique skills for complimenting the team: Flanker & Anti-Flanker. Self explanatory, you flank the enemy and for defense if you're on the flank of your team then you are preventing your team from getting flanked on that side.
  
  
• Playstyle tips: when presented with multiple enemies, make a 'sweep' by killing from left to right or right to left. If you manage to lock on different targets and shoot them fast enough then that's good but if not then shoot the ones who's a threat to you i.e. aiming at you or notices you before the rest does. You can try to master how to hip fire effectively to increase your killing speed at extremely close range, shaving off a second or two for aiming down sights if you can hit without needing to. If you have less than 4 seconds before the enemy react, return fire and kill you, you need to consider if you can kill them all within 4 seconds or not; if not then kill as much as you can within a couple seconds before quickly getting back into cover. Take on as many enemies as you're comfortable with at any single time, never more than you can handle. Don't try to kill everyone at once, if you need take out 10+ targets, take them out in smaller groups of like 2, 3 or 4 at a time. Try to guess how long you can stay out of cover to shoot for, if enemies return fire, don't keep shooting unless you know you can kill them before they kill you.
  
  
• Other tips: I usually don't have time to extend my finger to the numbers and I can't use the scroll wheel reliably under stress so I key binded Q to switch between primary and secondary, this allows for grenade canceling and switching weapons to be quicker. Out in open areas if you run into trouble at longer ranges, feel free to let other teammates who are better equipped or more specialized to push the frontline up for you to move up more freely. If you're impatient you can try to close the distance and take out the ones who are keeping the rest of your team from moving.
  
  
• Factors affecting play style effectiveness: how prepared you are vs. how prepared your enemies are, this effects how much time you have to kill them before they react. Controlling your weapon efficiently, how many rounds per target is considered optimal? How fast is your gun's rate of fire, how many enemies can you kill with one magazine? How much time do you need to have in between each killing session if you need to reload a completely empty mag? What do you have to do to make sure you have the time you need etc.

Primary (All loaded with AP)
Mostly up to what you feel comfortable using but I prefer:
-Galil SAR for its 35 rounds mag and highly controllable recoil for its relatively high rate of fire.
-AKM (altenative for AK74), its slower rate of fire is easier to control than the AK74, which can also be hip fired. Since the AKM has higher damage per round, you can kill people with 2-3 rounds at the most and so you only have to land about 2 rounds when hip firing instead of trying to land more than 3 rounds that is harder aim from the hip with the 74. Being able to kill more with less ammo and having to reload less is a bonus.
-AK74U (instead of AK74), very fast rate of fire that kills really quickly but running out of ammo is a concern. If you plan to reload often then carry extra mags with the carrier in place of the rig, but only if weight and short lifespan is not a concern.
Attachments: HBR, AP, foregrip, Holo/Kobra for maps with enclosed areas (faster target acquisition), red dot for maps with open areas (clear sight picture at longer ranges), flashlight for extra visibility and easier target identification when obscured.

Secondary
-Makarov with extended mag, low recoil and can be fired fast without much accuracy loss, low damage means you have to unload more bullets before getting a kill. I prefer 5 rounds burst per enemy so I can kill 3 people while knowing my bullet count, you can also load a new mag at round start to have 1 round left after firing 15 so you don't have to reload on empty and shave off a second but doesn't really make much of a difference.
-M9, you can invest in AP if you rely on it but I use my primary more often so I spend all my points there. I used to fire only 3 rounds burst per enemy to conserve ammo but after not getting consistent kills due to my aim being slightly off (hitting arm instead of chest etc.) under pressure, I turned to using the 5 rounds burst method same as the makarov. Being stingy with my bullets doesn't help me live longer, assuring I killed the enemy in front of me does.

Other equipment
-Grenades are entirely up to you, if you want to keep an incendiary for caches then that's up to your discretion. I tend to only have 1 smoke on me and the rest of my points are spent into the primary and pick up a molotov or an incendiary when passing by bodies after an engagement, saving points and as far as I'm aware items that aren't in your loadout doesn't effect your weight, stamina and movement speed.
-Standard gear are heavy armor and chest rig. If you feel like you will die no matter what armor you wear you can go down to light or if you feel like you really wanna bamboozle the enemy who uses AP you can go with no armor, but I highly don't recommend doing that. The main reason I use heavy armor is because it protects against smaller caliber weapons (anything that's less than 5.56mm) if they don't hit you repeatedly, like if you catch a stray bullet from some distance away for example. However when engaging you are likely to die no matter what armor you're wearing cause the enemy will continue to fire at you repeatedly until you go down.

Here's how bots usually work based on my observation and experience.
1.) They react to your presence mainly by sight and sound.
-For sight they need line of sight. It doesn't matter how far you are away or if you have trees and
bushes concealing you, all that does is increase the time for them to aquire you as a lock on target and shoot at you accurately, they will see you and shoot you with bot accuracy. The ways for them not to see you is if you have a solid object like walls obstructing your whole body or if you are in a smoke grenade's cloud, if you show a little bit of your head, arm or any body part sticking out of cover then they will still see you and shoot you.

-For sound they will hear footsteps, bullet impacts, gunfire and explosion. I'm uncertain as to how far the gunfire sound will travel for bots to hear and come investigate but for exploding caches the sound is almost map-wide and so in hunt mode almost all the bots will come to the blown up cache so you don't have to go looking, save maybe one or two too far away. Using suppressors also reduce your gun sound significantly enough you won't have to worry about them hearing you at all, they still can at close range but at that range they'd either see you before they hear you or hear someone else's unsuppressed gunfire in the distance. In a heated battle where people are engaging each other constantly, suppressed gunfire, footsteps and bullet impacts are muffled by the sounds of loud gunfire and explosions.

-The other way for them to notice you is if you shoot near them enough to supress them but not kill them, they are able to discern where your shots are coming from and return fire, assuming you don't kill it first and give it a chance to respond.

2.) They have a 'lock on' style target aquisition and their vision is kinda similar to like infrared imegery or something that just highlights you in their view. Once they lock on to the position where you are seen by the bot they will wait some time (depending on factors like bot's difficulty, distance, how much of your body is exposed and seen by the bot etc.) and lay down suppressive fire style salvo at your position that was seen. You can wait it out in cover and they will stop firing after a few seconds or you can relocate without being seen and they won't track you. After their suppressive salvo they might reload, move in on your last known position or both.

3.) The essence of firing and being under fire: always have a feel of how long you can stay out of cover to shoot for, it can range from a long time or just a couple seconds depending on how fast the bot locks on to you. After the invisible countdown timer has reached zero, the bot will start firing suppressive fire at your last seen position (the cover you ran behind). So if you know the bot will unload into the wall you're hiding behind, be careful about cover penetration and possible explosions. Either wait until the suppressive fire subside or relocate, either way you will get another opening to peek and return fire after that initial barrage is done so don't be impatient and walk into it and die for free.

So with that in mind here are some combat maneuvers that you could try:
The Killing Floor
-When defending your position: if you run dry on your primary and don't have time to reload a full mag then wait in cover near your last known location's entry point like a doorway and camp with your secondary, kill the first bot that enters then kill the ones that are right by the entrance, once you know have time, pick up the first bot's gun that's inside and nearest to you and use it to kill the rest. With this maneuver you essentially make a bot drop a gun for you close enough for you to reach safely, which is right at your feet but at the cost of drawing them closer.

The Merry Go Round
*Note: In all honesty the merry go round is a move for when you run dry on primary and need the extra time to pull your secondary out, because if we had ammo we'd just hold down left click and hip fire until it dies at that range, but anyway here's the boring explaination.
-When you're right next to a bot (extremely close) run behind the bot by going past on on its left side (your right) while switching to your sidearm then kill it by making sure you turn faster than it does (thanks to the mouse). With this maneuver you essentially try to add more processes for the bot to calculate and execute instead of merely shooting what's in their LoS in front of them like in their basic programming, and so you shave a second or two more to work with before you get shot. Obviously the bot will turn around to track you after it processes your movement's direction so pray you manage to kill it with the 1 or 2 seconds that you have. Also if going behind doesn't buy you enough time then you can circle around its right side again (hence the full circle, merry go round name) but you don't need that much time as to do a full loop in order to kill it and chances are you'll die before you finish the circle.
What determines if this works or not is the bot's difficulty (how fast they perfrom their action), you need around 1 full second to go past the bot and the bots can and have proven to be able to kill in less than that.
This has worked out for me before because the bot turned 180 or so degrees slower than me spinning the camera with the mouse, but I haven't played classic or hardcore for so long I don't remember the last time I did it. Now all I play is the super intense custom server with extra high difficulty cause of constant 300ms ping meaning constant 0.3s lag, that and plus server sending and receiving data at an inconsist speed with my poor internent connection. I might go try this maneuver again someday, when I have nothing else better to do. _(´-ω-`_)⌒)_
Edit: can confrim this move still works when the bot hasn't locked onto you (aiming, pointing the gun at you and is about to pull the trig) yet at the time you move into it, it's cute to see them turn the long way around when you've already circled past its peripheral sight range.