The level overview images are meant to be used by Teams to share callouts and by any player learning map layouts. None of my Guides are exhaustive and as such neither is the list of level overviews, I avoid maps deemed by the author as pub and I include maps played as TDM on known Youtube channels. Callouts are not fixed, so I won't post any sets unless it will be requested in comments. Just write the callouts of your choosing on the images after saving them locally.

• keep callouts short, monosyllabic where possible
  
• a generic structure is called 'house'
  
• use any unique structure or element, even a color used as lighting of an area, as long as they appear in only 1 place on that map; e.g.: 'lift' on biohazard, 'stairs' on lockdown; other examples: 'roof', 'ramp', 'bridge', 'ledge', 'perch', 'inside', 'outside', 'pipes', 'arena', 'secret'
  
• 2 mags only are called: back mag (towards the edge of a map) and front mag (towards the middle of a map)
  
• unique weapons are called by their name; R2 is short for 'AR2' as 'AR' is pronounced 'R' in RO/RU
  
• any room with computers or consoles is called 'computers' or 'console'
  
• teleports are called 'tele'/'tp' and 'tele end'
  
• the center of the map or the area with the most action is called 'mid' or 'main'; the bottom-most area - 'bottom'; top-most area - 'top'; bottom water area - 'sewer'; showers/toilets/sinks - 'shower'/'bath'
  
• a single long corridor - 'hall'; multiple corridors - 'tunnels' if rounded ceilings
  
• lostarena powerup - 'blue', 'cross', 'health'
  
• supercharger - 'super'/'charger', megahealth - 'mega'
  
• biggest stash if any - 'stash'

Rright click on the preview, select 'Copy link address', paste the link in your browser, right click on the image and select 'Save Image As'.

Most of the images are 1920x1080, but some have been sized down to fit the 2MB limit in order for the Steam Guide to accept them and host them here.
Since some maps are on multiple floors, not all floors will be displayed at the same time. As such, the level overviews are not unique and can be re-done with the preferred visible floor(s) by anyone following the instructions here: https://developer.valvesoftware.com/wiki/Level_Overviews, the 'Make the raw overview image' section. You might need cl_leveloverview only. I also needed r_skybox command for 'HL2: DM | Teamplay case study on caverns [w/ Noah]' YT video. https://www.youtube.com/watch?v=I-K94BEdntw
Why is the octagon one green? Short answer: Source games; there's examples of green ones in Counter-Strike: Source, too. Long answer: a lot of these came out green by default and it was difficult to tweak them to dark while still displaying them with all playable areas, and without roofs or missing sections, plus centering them (dm me if you ever encounter green). Octagon dark was missing a section.

https://youtu.be/EkmABS4OSlY
Main points: look for angles from out of vision for nades, orbs, and snipe angles for mag (watch Maxtasy's video and my video for those, lots of preset ones for main, charger, tp end, rpg door). And don't go main to feed.
Weapons: Xbow is mostly used to open RPG door and prefire prison. Shotty is used mostly while enemy is busy catching your orb, or as a followup if your previous attacks hit, so don't fully commit if you miss. Nades and RPG are also used as coverfire for charger, or coming out of RPG, or for taking the next RPG, even with a rolled nade while you are charging. Nades and smg nades can be used main up top and across, under the beams, just crouch before tossing them. There's an interesting RPG under the floor spot for the RPG door, just aim for the light fixture above the tele.
Lift: can avoid fall damage when jumping down the shaft if you grab the health vial; on VG and SF you can jump down and not trigger it.
Charger: can hide laser on railing while charging.
Tele: Following enemy into tp is risky, they could be waiting with a prop, explosive barrel, shotgun, nade. Also if you don't know where enemy is, tp is risky. It could be blocked by a prop, or enemy could be waiting like in the 'first shot' video where Nia waits for Dude. Or, again, nade.
Hops: From RPG door if you keep going towards prison and jump down, you can fit through the broken window, it offers more space to curve thus faster than the normal path offered by the entryway (see video). Another hop is from top mag to charger, land/bounce on the 2nd to last step so the stairs don't stop you or bounce you off them.
The 1st stage is the 'rush main through bottom vs RPG control, on repeat'. Aka feed. Whether done with shotty or nades, it must be preceded by attacks from cover. Through bottom it's worse since without air control you are an easier RPG target. Since nades are situational and not for everyone, check out my Gameplay Training Guide for 'Playing from behind' section, the 'Reset' concept, and 'Nade rush after spawn' section.
Instead of rushing, use orbs and mag as openers. Nades are OK, IF from out of vision. Don't fully commit if you miss, instead retreat, heal up, try again later. At this stage players also have a hard time gauging if enemy is still controlling main, so they will blindly rush main to get RPG, feeding some more. When enemy does lose RPG control, honor players won't even go for RPG, on bio, an RPG-heavy map.
The 2nd stage is the RPG counter, and the back and forth control. You are no longer feeding when enemy camps with RPG in main. The main counters to RPG are, in general, orb and mag. These can be accompanied by xbow, smg nades and nades. And shotty as a close range finisher. But if everything else is done right, this is not needed, enemy should be dead by all other means/weapons. At this stage, enemy doesn't feed either, and kills you with the same orb and mag angles when you camp with RPG, hence the back and forth. A lead isn't always easy to keep. Basic tips to holding main would be: knowing where projectiles might be coming from, not exposing yourself to too many angles while still having a somewhat overview of the entryways, and careful positioning to avoid ambushes.
The first 2 stages apply to tdm as well. Stage 1 gets worse. Bottom resources being split means less suit per player, easier to die to RPG if rushing on repeat. Best bet will remain orbs and mag. It only takes 1 player on team A to feed for team B to maintain RPG control.
The 3rd stage is 'looking for kills', or setting up for them. Whether ahead or behind in frags, camping main with RPG will no longer pay off as much, since good opponents will NOT rush main to feed. It might even be dangerous at times to attempt camping. The Basic tips to holding main need an upgrade. Another downside: few spawnkills in comparison to other maps where watching 3 points is possible (LA). Bio main only covers 2 areas successfully, water and undercharger. Tele end is not guaranteed, they can reverse spawnkill with barrel. Control points such as super, ar2+orbs and key stashes are still active. If you insist on holding main, gather the water orb if you have ar2, and/or the smg nade. You can spam if it's too quiet for too long, to ensure enemy makes SOME ggun or healthpack sound so you are not taken by surprise, and to ensure enemy is busy gathering health to stay alive rather than planning sneaky ways to attack you. This spam can be RPG or nades and this works for various styles, stationary or brief camping or constantly on the move, or a combination of these. Since camping is no longer as viable for keeping a lead, there are alternatives such as 'first shot' and 'running away'. Example: camp tele then take it when spotted in order to avoid all damage. Some players might slow the game down to keep even a 1 frag lead, or to set up for kills, but it will no longer be in main. In general, 'looking for kills' is done either when behind or comfortably ahead. Depending on players' styles, there are other ways of making a comeback besides chasing kills: slow down the game, or set up an ambush etc. No matter the state or the pace of the game, if at any point the enemy gets RPG control, just implement 'how to vs RPG'. And if you are in the lead, it's OK if they choose to camp, and it is still OK if they choose to hunt, as long as you can avoid their RPG by being on the opposite side of the map, or under them, or simply running away. It's all part of RPG counter. And keeping a lead in general.
The 4th stage is the 'mind games'. For some, 3 and 4 are intertwined, for others not so much. This 4th stage is about tracking the enemy's whereabouts and inventory, and determining their next location based on their pattern(s) and player tendencies. A pattern is specific to a player, it can be established in the first part of a game, or over the course of some games as that player shows a predilection towards a weapon, pace, or path. And preparedness is a counter. A tendency is broader, less accurate and can be done by many players. Example, a good number of players will take tele after stash sound cue. A tendency can even be per region. NA players will bait RPG more often than other regions. Pattern examples: First one or rather the result of a pattern was the 'here mousie mousie' video, as some players show a pattern in their first 2 minutes of a game, and very few backtrack or break pattern. After taking arena suit, player went blue instead of ar2, in 2 out of 2 situations. During the rest of the game, more often than not, they did the same. Chances were they were gonna do the same after arena suit sound cue towards the end of the game. When they were late, I got impatient hence me firing my ar2 at the wall. 2nd example is for bio, shoutout to Jerk. Enemy established a path after getting hurt at RPG door: prison, stairs, stash, tp. So the next time I assess enemy getting hurt around RPG door, either by my nade from out of vision or by another enemy, if I'm under charger I can just take 2 steps to bath and toss a well timed explosive barrel towards the bottom of the stairs. If the barrel is not there, on bio I should have either orbs or RPG. All maps have this wonderful 'enemy tracking' stage of the game. But on bio it's heavily gated by the first 2 stages. For more pattern and tracking examples on bio with commentary, watch Maxtasy's match analysis.
For stage 3 in tdm communication is important, and you don't have to give callouts, you can have binds such as 'charging' and 'me @rpg', plus listening to team mates is also part of communication. 'Looking for kills' applies here as well. Watch 'pwn stars vs Sanctuary Warriors'. Combine team are seen both in main with RPG or RPG access couple of times throughout, but watch what happens, and/or what they choose to do. For stage 4 in tdm enemy patterns and tracking will be harder but still doable.

The video below shows map specific things, like several RPG grabs, projectile angles, jumps, and other useful or fun things. It does not include prop jumping, nor xbow bounces. Comment if you know other angles for RPG grab!
https://youtu.be/gLdD2YX8mF8

Last edited on: 02-05-2025, added section: DETAILS: OVERWATCH.