Guide to Combat
As with all space station forks, preparation is one of the most important aspects of getting into combat, however there is no one size fits all technique to be better in fights. Make the best out of any situation your in. It is also important to remember you goals in a combat scenario. Are you trying to get survive? then simply running away is often a better idea than running at an armed gunman using your mop. Trying to arrest someone? If they are cornered and your at their only exit, simply wait for backup to arrive instead of charging into a room blindly.
Cover & Medicine
In extended gunfights, having cover you can retreat to and heal yourself is absolutely vital and will extend how long you can engage in combat. Most medicines require you to stop to use them, having cover you can avoid the enemy during this vulnerable time is very important. Gauze is one of the most effective topicals for dealing with gunshots, preventing bleed damage and healing the wound. For lasers and Energy weapons, you will want ointment. The medical department will be fully stocked with topicals and healing chemicals, and will be a good resource for dealing with antagonists who will have a long term presence on the station, such as dragons or colossi. Pills and drinks will take a few seconds to metabolize, often requiring you to take them shortly before you start taking damage to make full use of.
In melee combat, the closer distance makes it much harder to take cover and take time to heal yourself. In large fights, you can still often back up at low health and rely on other people to hold the frontline until your healed up and can move to the front yourself.
Dropping to low health will slow you down, making getting away harder! Be careful and keep an eye on your health at all times. "Fine" is about 60% hp.
Exploiting Weaknesses
All enemies have some sort of weakness you can exploit. Most crew will be susceptible to slipping: making soap, puddles, banana peels, and the clown's PDA useful items that can slow them down and cause them to drop their held items, potentially allowing you to disarm your opponent! Most magical enemies will take extra damage from the chaplain's weapons.
Range
Melee enemies have the biggest and most obvious weakness: their range. As long as you are 2~ tiles or more away from them they are entirely incapable of damaging you. Use barricades, speed, or otherwise stay out of their reach while you shoot them to take them down without taking a scratch. Lasers have the unique ability to shoot through windows and glass airlocks, if you have one, position wisely instead of standing in the middle of a hallway where you can be shot at by regular bullets or charged at by someone with a melee weapon.
Armor/damage types
Some species take extra damage from certain damage types, such as moths and heat damage. Shift click (by default) someone to quickly see their species. The in-game guidebook can be a valuable resource while preparing, but won't be too useful if your actively in combat.
Opponents can be lacking armor over certain parts of their body, Checking their sprite and changing which body part your targeting mid combat can be extremely difficult, but if you get the chance to examine them beforehand make note of any weaknesses they have! (keep note of glasses, masks, and similar items that provide minor protection to the head, or another body part and may make seemingly weaker spots tankier than expected). If your only goal is to get away, targeting legs to reduce their movespeed can potentially be useful.
Finally, even if someone is fully armored, keep in mind what damage types their armor provides the most and least protection against. Chaplain's armor, for example, is very weak to pierce! This will require some memorization, but even noticing that someone is very slow in their armor can give you an edge by using that slowness to hit them with grenades, or other slow projectiles, or using your own speed to take cover and heal. Speed is one of the most important tools in all space station combat!
Speed
As previously mentioned, speed is very important. It lets you run away from opponents who can defeat you, chase down opponents trying to get away, dodge attacks, or quickly get in to make use of melee.
Bolas
Bolas can be made with the makeshift handcuffs from LV cables, and some steel, or single use energy versions can be made by the security department. With a single throw, this item can wrap around someone and reduce their speed massively, almost entirely removing their ability to run away or dodge. Likewise, their slow speed means you can run away and entirely avoid melee attacks. A second bola will increase the effects. This can be countered by the freedom implanter from the traitor's and nukie's uplink, which will remove it instantly, but has limited uses.
Drugs
Some drugs, such as ephedrine, can massively speed you up, while shrugging off slows or some stuns. Likewise, other drugs like chloral hydrate, nocturine, or a whole host of overdoses can cause your victim to suffer reduced speed, fall asleep, vomit, or otherwise hinder their combat effectiveness. Injecting these will typically require a hypo or syringe gun, as syringes and jet injectors require them standing still for a short time.
Slips
Puddles, banana peels, clown's PDA, random mutated plants, and bananium flooring will cause people who step on them to slip and fall if they aren't walking slowly. Space lube is extra slippery and will slip even people who walk slowly. Slipping causes items to fly out of their hands, and for them to fall over, slowing them massively. Activated magboots, janitor galoshes, and No-Slip shoes from the uplink are the primary counters to this.
Utilizing Strengths
Depending on what department your in, and your own knowledge, it may be better to offer support than to run into combat yourself. Doctors can provide frontline healing, engineers can setup barricades, cargo can order and distribute weapons, and service can keep morale high! Use tools in your department to your advantage. Likewise, if your playing command, ordering crew around and ensuring they stay organized and on task is a bigger boon than running in with your knuckle dusters.
[this is a very broad concept, so I think it would be ideal to keep combat tools in each individual section such as cargo or medical.)