I saw Daniel's post and I thought I'd share one of my own spots and the known ones. The main goal of these spots is to kill innos without them hearing the C4. You have to, of course, defend the C4 yourself. Innocent Motel: In spawn if you face the front (as if you're looking at the reception/front desk) there should be a pair of steps in each side of the room. The steps in the left have a gap in the right (a gun almost always spawns there). If you place a C4 there it will kill all the people near the tester and (partially) the T room. This one is aids for the detectives: Below the D room there should be a pool of water, place the C4 as high as you can (jump to get it higher and right click to place it). If you jump once again and press E on the C4, the GUI should stay if you go back down and then you can arm it. Go to the crates in the corner to defend it. In the basement you can place a C4 ON ALL the steel beams in the ceiling. Just jump and right click on one of the faces of the beam. 67th Way To kill people in the D room, go to the dark room above the D room (inside the red house). There should be some crates and such. You can either plant it inside the bloody room or against the wall. Or you can plant it on the carpet where the guns spawn. If there is a player camping the secret room near the tunnel (where you hit the electric box with the crowbar), plant the C4 on the wall facing the direction of the secret room by the gas chamber. If there is a player camping one of the jail cells, plant the C4 BEHIND the cells or on the roof and just camp the cell doors. In the first cell there's a hole where they can go down, just place a tripmine where they would hit the ground. You can also plant a C4 in the vents underground to kill players that are near the flood room or outside the D room, just plant it in the center of the vents. Clue You can place it anywhere to be honest. But what I like to do is to spend my two credits by placing a C4 in both rooms in spawn (it's on the back). Others: Life the roof: If there are players in the pool area below the elevator, place the C4 on the elevator floor and time it so the C4 goes down and explodes without the innos able to defuse it. Jump to the right side and get to the ladders to escape. Note: You can see the pattern here. The majority of the spots kill players behind a wall, and above or below a floor. On all maps you can determine a way to do this.
In hairy house the best place to place a c4 is right above the door frame in the garage. It will get all 3 floors of the house and the most popular spawn points. it's basically the quickest way to clear the house.
Climb to this big box on the attic, put C4 on top, I've never had that defused. 10 minute on spawn xd There's this cabinet in a room with tiled floors and a fireplace, It's to the right of spawn, open the cabinet, put C4 in it, close the cabinet. did i guess rite
The liquor cabinets in the basement Gonna leak my innomotel spots soon, which are typically only found by people that I've told them about it. Fuck innomotel nuke it to hell EDIT: Jump while placing a C4 here, to get it as deep in there as possible Spoiler: 1st spot Really hard to defuse when you put one inside this vent, as you have a high chance of slipping and ending up on the roof. Have to be careful while placing it. Spoiler: 2nd spot Last spot that I use pretty rarely but it's good if there's 20 people in the Det room or near it. Pretty much impossible to hear and no one ever checks back there. Spoiler: 3rd spot I like the first two cuz they're near the middle of the map so they cover a huge area.