Bloodlines calculates velocities and acceleration on a per frame basis, so the higher your framerate the easier it will be to gather and maintain speed. By default, the game sets the max framerate (fps_max) to 300. However, a side-effect of having a high framerate is that physics-based objects such as doors become unstable and either won't work properly or will clip into you, permanently trapping you inside of it.
To fix this issue, we bind fps_max “#” to the side mouse buttons, and switch between 60 and 300 fps throughout the run. See Setting up the Game for details.
In Bloodlines, speed is shown in units per second, or plr vel. In addition to being tied to the FPS, speed is also determined by which key you're using to move, and what model character you're using. So male and female character models have varying speeds depending on the movement. Female models are used because they are faster on the ground than male models on average. However, yet to be explored is that male models can turn faster than female models in some instances.
|Female Crouched||Male Crouched|
By walking forward and rapidly tapping left and right in succession, male characters can reach an average of 230-250u, and female characters can reach 250-260u.
By walking forward and holding a strafe button into an angle on a wall, you can gain velocity. Turning towards the wall will increase your velocity until you get higher than roughly 15 degrees. Males can reach about 300u on left/right sides. Females can reach 310u on the left, and 320u on the right. This is very useful for setting up bhops.
When in a vent that is angled upwards, jumping will cause you to gain speed. Like wallstrafing, by colliding with the ceiling the character will be pushed forward. At default FPS, you can boost as high as 850u.
Looking straight up and holding forward to climb a ladder to yield about 101u. If you hold forward and a strafe key into the ladder while looking at about a 45 degree angle, you can go to about 158u. This applies to both gender models.
Bunny Hopping is a movement technique where the player increases their speed by consistently jumping while air-strafing to gain velocity. This is the main movement method for many games on the source engine, including bloodlines.
To successfully bunny hop in Bloodlines you need to strafe using the left/right movement keys (A/D typically) while turning your mouse in the same direction while jumping as soon as you land. For example, if you are strafing right, you turn your mouse right. Doing so will allow you to gain speed upon every jump if you continue to jump at the right time to negate the friction of landing. If you hold forward (W typically) it won't work. As mentioned above, the ability to gain speed while bunny hopping is determined by your FPS.
Bloodlines changes the way it behaves with jumping when you use either the spacebar or the mousewheel. It's important to have jump binded to both. Jumping with spacebar will give you a higher, longer jump. Jumping with the mousewheel will give you a lower, shorter hop. The former is useful to begin bhops as you gain a lot of beginning momentum from performing a circle jump. The latter helps to build up speed by jumping quicker, and using the mousewheel helps to send many jump commands per scroll, so you have more room for error on timing the jumps.
In the cl_showpos info panel, we can see the plr vel. at the bottom. This will tell you how many units of speed you are moving per second. The velocity you can achieve differs depending on which level you are on, but a high units of speed would be 600u.
Crouching or ducking is an important movement in Bloodlines since doing so in the air moves your character's hitbox upward. When playing in first-person, your point-of-view does not always represent exactly where your character's model/hitbox are. So when you crouch while in the air, the engine shifts your model/hitbox up higher to simulate the effect of pulling your feet up into a crouched position. This can allow your hitbox to activate level triggers that are located through other objects. You can bunny hop while crouched and stand up in the middle of a hop and keep your speed, as long as there is room for your legs below. Crouching also activates the sneaking stat, and allows you to execute an enemy from behind if they are looking for you.
An example of where hitbox shifting is important is on the Santa Monica Pier. By circle jumping and crouching at the right moment, you can jump over the locked fence and enter the Surfs Up quest early. Another example is in the Ocean House Hotel, where jumping and ducking over the stairs can skip the bottom basement section of the level.
Taking damage from explosions or bullets in the back from the back can propel you forward and upwards, depending on the circumstance.
When escaping the bomb timer during the Sabbat Warehouse quest, a water tower is along the path out towards the trains. A box, with a gas canister inside, is supposed to explode when the player shoots another gas canister under the water tower. If timed correctly, it is supposed to kill the Sabbat Vampire after you. If you jump and duck into this box you can trigger the explosion and dramatically gain both height and velocity.
When you get stuck permanently inside of an object, if you quick save and then reload your character will be moved upwards. By continually quick saving and loading after getting stuck, you can climb up so long as you are still inside of the object. On some levels, once you reach the end or a certain point within the object, your character will be warped upwards and fall downwards on top of the level.
So far the only application of this glitch is used in the Hollywood Netcafe to obtain the 2nd Snuff Tape early.