Gaining entry to areas above your clearance is an important skill. Sometimes you're a traitor looking to loot stuff, a gangster looking to tag stuff, or a revolutionary looking to raise hell. Sometimes the traitor is chasing you and you need to get away fast. Sometimes the station spawned without an engineer and someone needs to get the power working. Sometimes the AI has gone mad and has locked you in a room filling with deadly neurotoxin. Sometimes you just want a damn burger and nobody has kitchen access. In any case, this is a collection of ways to break into places. Most of these methods have more detailed guides elsewhere on the wiki, the purpose of this article is to pull them all together.
Methods
Prayer
Equipment required: None
Method: Hit the info tab, then IC, then pray, type a prayer. God may respond and help you. Or you might explode for your impudence. Worth a shot if nothing else will save you. (Note: This actually sends a message to a logged on admin who may or may not respond by doing all manner of things, if this is your first resort rather than your last resort they will quickly get fucking tired of you and you are likely to wind up on fire.)
Tailgating
Equipment required: None
Method: Wait for someone to walk into the area you want to access. Follow them in. Try to explain why they shouldn't call security (or wear a disguise so they don't ask)
Persuading
Equipment required: None
Method: Talk someone into letting you into a restricted area. Remember that this is a roleplaying game and that people should be playing characters; try to work out what makes other people tick. Maybe the security officer likes drugs enough to forget about his job for a little while, or the scientist might be susceptible to flattery, or the chaplain might sneak you in to places if you go to all of his sermons.
Looting
Equipment required: A corpse with loot
Method: Did you know that you can loot corpses by clicking and dragging from them onto you in the main window? Do so and click on items to cause them to fall to the floor where you can take them. Grab someone else's ID card from their cold dead body and use it, or grab tools to use the below methods.
If there's not a corpse handy, you can always create one. Just remember that killing people while not an antag is extremely bad form.
Pickpocketing
Equipment required: None
Method: That looting thing? It works on living people too. The downside is that it displays a message saying that you're trying to do it, and it fails if they move or do anything. It can still work on someone who's deep in conversation, busy writing a PDA message or endlessly toiling at the genetics computer. Bonus points if they're distracted writing the PDA message to reply to something you sent them. Or you can just stun them: A few hits from a stun baton or disabler will put someone out long enough to loot their ID.
Note that actual pickpocketing, as in stealing from someone's pockets, does not produce a message unless the person moves. But not many people carry their IDs in their pockets.
Remember that robbing people while not an antag is also bad form.
Ask the AI
Equipment required: A radio or a nearby holopad (though an AI upload and custom rule module improves your odds)
Method: Ask the AI to let you into a place. Under Asimov, its second law requires it to follow any orders from humans. Some AIs assume pre-shift standing orders to enforce space law, this is against server policy! If they're being really obstinate about it, consider asking an admin to remind them of the rules. If you can give a good reason (especially ones that hinge on saving human lives, which is law one) then all the better.
Threaten the AI
Equipment required: None (though some sort of weapon is a boon, as are yellow gloves)
Method: The AI must act to prevent harm to humans, even if it means ignoring the captain's orders. If you can make a credible threat against another human if the AI doesn't open the door then it must do so. However, threatening to suicide or harm yourself to get the AI to do something is against server rules. Don't do it!
Tableclimbing
Equipment required: None, though a blunt object is helpful
Method: Drag yourself to a table that is blocking your way. This will stun you for a few seconds, so be wary. If the table isn't blocked by anything, you're in! Most of the time, however, there will be a windoor between you in the room. Dismantle it, break it, emag it, open it (but if you had access, why did you need to tableclimb in the first place?)
Breaking a window
Equipment required: A solid object or projectiles. The emergency air tank in your emergency box will do, a fire extinguisher or axe or revolver is better. Toolboxes are also a good choice. Insulated gloves are helpful if you plan to break into a secure area.
Method: Put item in hand, click on window repeatedly till the glass breaks. If you have a weak weapon like an air tank, this will take a comical amount of time. Click on the grille repeatedly till it breaks, or use wirecutters if you've got them. This is a really obvious and noisy method and you will be locked up if security catches you doing it. Probably the most expedient way to escape a rogue AI though. Some windows may be reinforced with electrified grilles, which will shock anyone who tries to break them without protection, as well as anyone else nearby.
Breaking a wall
Equipment required: Welding Torch, Wrench, Screwdriver
Highly recommended: Welding Mask, Hardsuit Helmet or Sunglasses
Method: Click on the welding torch to turn it on, click on the wall to weld the panels off, change to the wrench, use it on the girders to disconnect them, then use a screwdriver to dismantle the girder. Welding without eye protection eventually makes you go blind, though you can do it once or twice without harm.
Bonus Fun: If you skip the screwdriver step you can apply some metal to the girder, such as the metal left behind from welding, to turn it into a secret door. This will open when you click on it with an empty hand, but only you will know it's there. You and anyone wearing meson scanners, so don't do it near engineering.
Breaking a reinforced wall
Equipment required: Full mechanical toolbox (except the analyser)
Highly recommended: Welding Mask, Hardsuit Helmet or Sunglasses
Method: Use items one at a time on the wall to tear it to pieces, remember to turn the welding torch on when you use it and use eye protection. Ready for this?
Wirecutters, screwdriver, welder, crowbar, wrench, welder, crowbar, screwdriver, wirecutters, wrench, screwdriver.
Bonus Fun: The final screwdriver step can be skipped, then you can use plasteel on the frame to make a reinforced secret door. Your own private way into the armory.
Ghetto hacking
Equipment required: Screwdriver, wirecutters, crowbar
Method: Find a door you don't care about, use the screwdriver on the door to open the panel. Use the wirecutters on that to open the wirecutting menu. Cut wires one at a time taking note of the result:
- If the bolts drop, this door is sealed from you forever, make a note of the wire so you never cut it again, keep using the door for practice.
- If you get an electric shock, this door is electrified forever, you can take about two such shocks, the third will kill you. Don't touch this door again, move onto another, heal your burns, find a way to warn the crew about the door if you're a good guy Note the wire so that you never cut it again.
- If the test light goes off, you have cut the main wire! Note the wire, close the window, wonder around for a bit (10secs) and come back, use the wirecutters again. If the test light is still off you've cut the backup wire earlier, find another door, cut this wire first then cut the ones you cut before one at a time until the light goes off and stays off, note the wire that does this as the backup wire. If the light is back on use the same door and cut wires one at a time until the light goes off again, now you've found the backup wire.
- If anything else happens, ignore it and carry on.
Once you know which the main wire and backup wire are you can cut both of them to cut power to the door, then you can use a crowbar on it to open it. Crowbar the door shut and screw the panel shut once you're done with the door to hide your activity. You may also wish to repair the wires you cut, but reconnecting power wires results in electric shocks, so have a lot of health and have ointment ready.
Note that reinforced doors have secure wire panels, opening which takes some time and requires you to use a welding tool.
Improved hacking
Equipment required: Screwdriver, multitool, crowbar
Method: As before, but use the multitool instead of the wirecutters, use pulse instead of cut, this results in the following improvements...
- ...if you hit either the main power wire or backup power wire the door is depowered for 30 seconds. This is long enough to crowbar it open and be on your way. You don't need to worry about it closing behind you since you can pulse it again on your way out (which is bad to do in the 10s window in everyman hacking since you'd electrocute yourself reconnecting the mains wire to do it again)
- ...if you electrify the door, wander off for 30 secs and come back, it should be de-electrified now.
- ...if you drop the bolts you can pulse the wire again to pull the bolts back up.
Safe hacking
Equipment required: Screwdriver, multitool/wirecutters, crowbar, insulated gloves
Method: Insulated gloves make you immune to puny electrocution. Follow the guide above but don't worry about getting injured. If you're in a hurry, once you learn which wire bolts the doors you can hack in a hurry by cutting every single other wire without worrying about learning which is which. With gloves there's no excuse for not fixing the door behind you though.
Depowering
Equipment required: Wirecutters, crowbar, probably insulated gloves
Method: A room without power is very easy to break into; all you need to do is crowbar open the doors. There are many ways to depower a room. In increasing order of viability/traitorousness: waiting for the power to go out naturally; cutting a wire (usually in maintenance) leading to the APC; turning off the APC (requires engineering access); destroying the APC, whether manually or via an explosion; planting a power sink.
ID upgrade
Equipment required: High level ID, HoP access or captain's quarters access
Method: Put your ID into the computer, put the high level ID into the computer, click on the computer, click on modify ID, change the job to "captain" giving you access to all areas, change the job to "custom" and rename it to your original job. The ID is indistinguishable from your original but opens all doors. The fastest possible means to access new areas once you've done it, but normally requires some illicit access to get into a position to do it, and will be incredibly obvious if anyone sees you. You can also convince the HoP to do it for you, on the off-chance he might actually say yes.
Wall melting
Using thermite.
Equipment required: Chemistry access, lighter/matches/welder
Method: Grab a beaker from the beaker box and put it into the chemical dispenser. Add iron, aluminum and oxygen to the beaker. It should bubble. Dispense the beaker, it now contains thermite. Slosh the beaker over the target wall and apply fire. The wall will ignite and eventually a hole will form.
Since getting into places is what you're trying to do in the first place, you might not be able to swing chem access. Never fear. You can also ghetto chemistry the three thermite reagents from public sources, if you have enough money for a soda. Buy a canned air (or scavenge red toolboxes for glowsticks), any other soda can, and get some iron from spare metal or medborg lollipops. Empty and crush the soda can (Боевой режим 
Включается при помощи клавиши 4, выключается при помощи клавиши 1 или может быть переключен при помощи клавиши F при стандартной раскладке. Нажатие левой кнопки на людей пустой рукой с включённым боевым режимом приведёт к удару 
или приведёт к помощи 
если он отключен. Также позволяет вам не меняться местами с человеком или толкнуть вас если вы столкнулись., target your own head, click yourself with the can). Use the holodeck's emergency medical facilities: beakers, syringes, grinder, and the ChemMaster, which can separate and bottle the reagents.
Teleporting
Equipment required: Hand teleporter
Method: Stand next to the wall of your target room, click the tele, choose the random ("dangerous") setting and hope it doesn't pitch you into deep space. It might work. If you have EVA gear you can try it over and over till it does. Note that the hand tele has a cooldown after using it several times, and that anyone can follow you through the portal.
Advanced teleporting
Equipment required: Teleporter access.
Method: Get a tracking beacon to where you want to go, set up the teleporter and zap yourself there. Make sure you have a way out. Downside: Only scientists or hackers will reliably be able to pull this off, and if you're already hacking it may be more efficient just to hack your way in. Though it lacks the element of surprise.
Screw subtlety
Equipment required: Toxins access
Method: Make pressurised oxygen and heated pressurised plasma (a guide unto itself) combine them with a combination tube and add a timer to the tube. Place the device next to the unwanted door, activate the timer and run. If you're a traitor, a syndicate bomb or C4 obviously works as well. This will rid you of a door, any nearby walls, any nearby people and most of the station, as well as get you banned if you're not antag.
The monkey gambit
Equipment required: Monkey syringe, genetics access or being a changeling.
Method: Turn yourself into a monkey, stand on an air vent, hit info->monkey->enter vent to crawl through the vent to any other room on the station. Alt-clicking a vent also works.
Downside: You can't carry equipment through vents so it's useless for looting. The vents may also be full of gases that will kill you (or empty of gasses that you need to breathe).
Other downside: You are now a monkey.
Other methods
There are other methods, though most have such significant drawbacks they're not worth it. These include...
...rerouting the disposal pipes to your location
...building a mech and drilling through the walls
...getting turned into a wraith by the chaplain/wizard/cult
...ganking a teleportation wand/scroll off a wizard
...getting killed and raised from the dead in the target area. (for when you really want into medbay and somehow can't just wait for someone else to open the door for whatever reason)
...getting arrested, hoping someone remembers to set the timer but forgets to check that you leave when it expires. (good luck)
...researching a wormhole generator, building a mech, installing it, creating a wormhole, jumping in and praying.
...turning yourself into a hulk (required genetics access) and bashing your way through.
...growing bluespace tomatoes, squishing them and hoping to get lucky
...waiting for the fairly unlikely wormhole random event, hopping the holes, and landing at your destination and not in space
...hoping a meteor strikes the outside of the station and EVAing your way in.
...putting a grenade in a braindead person along with a remote signaling device (for the love of mike only antags)
Always experiment to find out more!