do you really need the ability to jump? do you really need responsive movement? do you really need to feel lightfooted?
being slow is fun. it puts an emphasis on the much smaller movements and punishes wrong steps and improper placement. it forces you to carefully consider your next move as you won't be nimble enough to pull out if you fuck up. it teaches you patience. in a pvp context, it lends itself extremely well to letting one who can position themselves properly win over one who can aim better, shifting the requirement for victory from reflex to perception and planning.
the lack of a jump button pairs well with slow movement. not being able to jump doesn't mean that the environments should be flat, you can still have lots of verticality by only allowing the player to climb ledges, stairs, ladders, ropes or cracks. bonus points if you put tall ledges into your maps that can only be climbed if two players cooperate (metal gear online 2 has those, they're great).
what to do with an unbound spacebar? you could use it to dive forwards, à la max payne, or to roll out of danger, or to dash in any direction, or to get into cover (i like cover shooters, come fight me about it), or to interact with the environment, leaving e and f free to execute other actions, or whatever else you could think of. or you could leave it unbound.
swat 4 is the only truly "slow-paced" first person shooter. name one slower fps game and you win a kiss on the forehead.

ps: i feel like the concept of aiming-down-sights belongs to this discussion, as it is usually directly tied to the pacing and movement mechanics of a game. fast games don't need it. slow games are made even better when you can only shoot while aiming (REvil, project zomboid and metal gear solid do this), but even slow games don't need it (swat 4 does not feature ADS).

You're wrong about this

it lends itself extremely well to letting one who can position themselves properly win over one who can aim better

slower movement speeds put even more emphasis on aim. In faster paced games, the aiming normally less precise, and you can compensate for lack of aim with good movement. In slower games like tac shooters, you basically sit in a corner and purely move your mouse to click heads. Which leads me to my point:
There are no fps games with slow movement, because to my knowledge, there are no fps games which limit your turning speed (beyond the natural limitations of turning with an analogue stick which is a fundamental flaw of that control style and gyro is superior). You wouldn't want a game where it takes you ages to spin around and aim that would feel terrible. Once you get used to a faster and more expressive movement engine, going back to a slow and boring movement engine feels the same as if you weren't allowed to move your mouse as fast as you want to aim. I should be able to place myself anywhere on the map I want to with enough skill, just like i should be able to aim however I want with enough skill.
Doom doesn't have a jump button and there's a reason they put one in quake. Swat 4 is gay copaganda.

""bad" movement" and slow movement are two different things

your game can have fast but clunky movement or slow yet engaging movement
it is not about the speed or the range of movement, it is about how well the movement works in your game

I've been spacemarine 2 recently and surprisingly there's no jumping in that game and it really doesn't bother me, really makes you realise how unecery of a mechanic it is in most games.

>>3
clunky movement is fun and can work to improve the feels that the game wants you to be feeling. amnesia the dark descent wouldn't be anywhere near as scary as it is if it didn't have such shit movement. movement does not have to work well by itself to work well within the game.

>>2
you make a lot of sense. i hadn't really thought of the importance of the headshot in most fps games because i was narrowmindedly only thinking of games with extremely low ttk where bodyshots are just as good. i don't really play any headshot games 'cause i think the headshot should be a flourish or a demonstration of one's ability, and not the baseline for dealing enough damage to win the game. the torso and limbs are full of vital organs and blood vessels, why should the head be the only part that matters? might be fun if you see games as just skill toys but i don't.
a way to restrict the player's ability to aim that i think is fun is to tie accuracy to the player character's stats and chosen weapon. it's a bit more rpg-ey and wouldn't fit many uses cases or user tastes, but it works well in project zomboid and cataclysm. i've never seen a first person shooter that does this, but i'm sure that it could work in the context of a class-based pvp game. for example, a pointman character might move faster, be less affected by movement inaccuracy and stabilize faster when coming to a stop but they would have worse base accuracy than the average grunt, worse by such a degree that it would make it difficult for them to use the same weapons at long range. it would strengthen the need for teamwork to know that you won't be able to hit that shot but your buddy who's playing a marksman will. you'd always want to be in a pair with a character who can compensate for your weaknesses.
i don't regard faster movement as necessarily being more expressive. there's a huge amount of player expression involved in the micro-movements required by slower games. the smallest step can mean a lot. even choosing to remain still can mean a lot. successfully evading visual detection in a pvp situation by means of camouflage and immobility is a rush, and my preferred method of expression-through-movement.

because to my knowledge, there are no fps games which limit your turning speed

escape from tarkov limits the player's turning speed based on carried weight. i hate that game because of the first aid system being too lenient and the insane power gap between low-end and high-end ammo and what they did to the mosin nagant but it has a few good ideas regarding player movement.

Swat 4 is gay copaganda.

if that's how you wish to see things. i don't think any sensible person would play the game and come out thinking "wow, cops are so cool, i wanna be a cop too!". it seems like a very shitty job. the police in-game aren't painted as heroes, they're just guys with guns who use violence on those who go against the established order. cops vs suspects is a setup for fun gameplay involving faction asymmetry. though i guess it's easy to start seeing em as heroes when you compare em to the people you're arresting/trying to arrest. anybody could look like a hero next to drug dealers and serial killers.

slow games are made even better when you can only shoot while aiming (REvil, project zomboid and metal gear solid do this)

Not sure about the later ones but you can shoot without aiming down sight in mgs1 2 and 3. In fact in mgs1 whether or not you can ADS at all depends on which weapon you're using. These games don't conform to the regular concept of ADS, instead their "ADS" is simply a combination of raising a weapon while being in first person (each action is its own toggle), so not really the same thing. You're right that some weapons automatically bring you into first person and therefore functionally force you to ADS while using them, but most don't work like this.

>>6
i was thinking more of mgs4/mgo2. when you hold a weapon in this one your character keeps it in the low ready position. pressing the attack button while your weapon is lowered will initiate cqc. cqc moves depend on the weapon held, long guns will only allow you to bash with the stock but most other weapons will allow you full range of cqc attacks. you can only fire while aiming, either in over-the-shoulder view or first-person view. thanks for clarifying about the earlier games. i haven't played them yet but i've been meaning to, they've been sitting on my ps2 shelf untouched since i bought them a few months ago. life happens, haven't had any time to invest into those, and won't for the next few months.

It depends on the game and setting. Realistic or CQC games often NEED to have slow movement for immersion and realism purposes. Imagine you had Titanfall or TFT2 movement in Swat 4 or Insurgency Sandstorm XD. But still I think jumping has it's place even in these 'realistic' games (mounting over windows, jumping over obstacles etc). The solution is just to implement a stamina mechanic that prevents you from jumping again for a set period of time (just to prevent it from being abused)

>>8
the counter to prevent jumping from being abused in titanfall2 was a sniper 6 miles away.

>>5

In the genre of hyper-realism, if you get hit in the leg or even in the abdomen or chest it still isn't going to be as crippling as a true 'headshot'. Modelling the hitboxes for each individual organ or the dozens of status debuffs is not a easy undertaking which is why most games over generalize and label the head/torso as a singular hitbox. The closest I have seen is ARMA with ACE mods (Advanced Combat Environment) where you have shrapnel, lacerations, puncture wounds etc.

For arcade shooters where the emphasis is placed on other game-play elements like movement, killstreaks and mechanics, they tend to have headshots to make the game more 'competitive' and less boring. You always have this feeling that even when the odds are stacked against you, you can maybe clutch this round if you get lucky and hit all head. TLDR, headshots have their place. It's just that sometimes they are poorly implemented

>>10
when it comes to hitreg systems in games, the most complex i've seen is present in an abandoned unity project named "crisis response". this project's physiology system is very advanced and not very well optimized, so you'll need a powerful cpu (8 cores should be more than enough) to handle more than a few occupants in the building. it doesn't put too heavy of a load on the gpu though, which is pretty cool. the physiology system handles breathing, heart rate, blood volume, blood pressure, blood oxygen, physical work and physical shock, as well as concussions and brain damage. if you want to know more about how it works, i'll give out an explanation based on my observation, but the dev explains it (and probably better than i do) in this video: https://www.youtube.com/watch?v=H7BKGlj-kNs

there's an impressive amount of different hitboxes. there's one for almost every major organ (heart, lungs, liver, kidneys, brain), there's one for each major blood vessel (excluding those present in the arms, since arms cannot be targeted), there are hitboxes for sections of the spine (cervical, thoracic, lumbar) as well as for leg bones (femur, patella, tibia. the fibula seems to be absent.) and there are generic ones for limbs. there are no hitboxes for the pelvic girdle, which would be an immediately disabling hit, similar to the spine, or for genitals.

the most important aspects of the system are that:
00>a round or pellet can trigger multiple hitboxes and change trajectory within the body.
01>very painful hits and strong concussions are immediately disabling.
02>leg hits greatly slow movement and cause massive blood loss if an artery is severed or a bone is broken.
03>a single torso shot that doesn't hit any vital systems with a high-velocity rifle round is still painful enough to immediately disable most occupants, in most cases (there's a slight bit of randomness involved).
04>heart, brain and spine hits are immediately disabling, regardless of bullet mass or velocity.
05>kidney and liver hits are not always immediately disabling but cause massive blood loss.
06>lung hits perturb an occupant's respiration cycle, which in turn perturbs their heart rate and reduces their fighting ability by making physical work more strenuous.
07>non-brain headshots are usually immediately disabling because of the concussion applied by the force of the bullet. if not immediately disabling, may lead to massive blood loss by severing the carotid artery.
08>concussions disorient occupants and will fade away over time. brain damage disables occupants and is permanent.
09>buckshot absolutely shreds people. 9 pellets are fired from each shell, and each pellet is comparable in power to a .38 special round.
10>low-velocity rounds require multiple hits to disable an occupant if none of the hits are dealt to critical systems.
11>magnum revolvers do not mess around.
12>different ammo types have properly different effects. fmj just tears through everything but doesn't leave the most devastating wounds. jhp can penetrate doors, walls and sometimes armor (depending on caliber and velocity) but it will be greatly weakened after traversing an obstacle, however it has a better chance of severing arteries when it hits flesh targets in regions where arteries are present (or at least, that's the impression i get). xp is fmj on crack. rip splits into petals and causes multiple canals and exit wounds from a single entry wound, though it will also split when penetrating obstacles which makes it nearly impotent due to serious imprecision when shooting through doors or tables. subsonic is usually heavier but is slower. sometimes it's a little bit slower, sometimes it's a lot slower. for example, 9x19 jhp has a mass of 7.5 g and is flying at a velocity of 411 m/s, whereas 9x19 jhp subsonic has a mass of 9.5 g and is flying at a velocity of 302 m/s. this is not a rule that applies to every caliber. 5.56x45 is an exception. 5.56x45 jhp has a mass of 5.0 g and is flying at 850 m/s, while 5.56x45 soft point subsonic has a mass of 4.1 g and is flying at 305 m/s. this leads to an immense disparity in the energy output of supersonic and subsonic 5.56x45 rounds.
13>armor vests and helmets can catch rounds but will not prevent trauma from non-penetrative injuries.
the ttk ends up being very similar to that of insurgency (2014), where your basic intermediate caliber rifle will down an armored opponent in a single hit to center of mass.

there's also a worryingly high level of audiovisual detail to represent the damage that is being dealt. occupants will physically react to injuries, holding onto wounds, tensing up from pain, jerking violently from seizures induced by blood loss, exhibiting signs of decorticate or decerebrate posturing (not always symmetrical) or entering a state of fencing response on strong concussions, either contracting or overextending limbs on head hits, or dropping like a puppet cut loose from its strings when the brain is destroyed, and they'll cough up blood or do this really gross wet breathing when their lungs or airway are damaged. blood will leak from head orifices when related systems are damaged. when blood gets into the respiratory system, it will leak from the mouth and nose. when a concussion is strong enough, it can leak from the eyes, mouth, nose and ears, though it is not guaranteed to leak from all orifices at once on every strong concussion. consciousness is also a thing that is handled by the system. i'm not sure of exactly how it works, but it is tied to every other bodily system. an occupant can pass out from blood loss, or lack of oxygen, or a strong concussion, or intense pain. loss of consciousness is often accompanied by seizures but both reactions are independent from one another, as an occupant can be seizing up while still conscious. blood will drip on surfaces and the game uses fluid dynamics to simulate puddles. all of these systems lead to instant and very visceral feedback for hits. if the portrayal of violence in insurgency sandstorm made you feel uncomfortable (or induced in you some morbid kind of fascination), this game cranks it up to eleven.

this complex system could be stripped down and refined a bit, down to the armor, ammo types, hitboxes, bleeding and concussions, and adapted to 3d to fit into a team-based pvp game that centers on small scale (8v8 or 12v12 seems good) warfare where avoiding incoming damage and providing first aid to injured and downed team members would be rewarded by using a scoring system. teams would compete for an objective, which would be the primary victory criteria, but with a catch. there would be a secondary victory criteria, which a team would win not by having the most kills, but by being the one with the healthiest team members at the end of a round. this would give a similar feeling to that of folk racing, where racers are rewarded for being the fastest or meanest (or in this case, safest) racer on the track. unfortunately, my understanding of how games are made is fairly limited, and i find code completely alien, and making a game alone is way out of my skill set (i'm a n00b at texturing, sound design and lua, completely ignorant in other aspects) so this idea will never become more than just an idea.