Believe it or not, one can stay safe as a survivor but you need to be careful.
1. Get Free Running ASAP. Stay off the streets.
2. Keep an eye on your neighborhood. If you log on and find all zombies or dead bodies all over the place all of a sudden, move. If you log on to find 20+ zombies standing outside your safehouse, they're not there to sweep the driveway. Move. If you log on and find every building in a six block radius busted open except for yours, there's a good chance that yours is next.
3. Pick a good safehouse. Train stations, banks, warehouses, motels, schools and buildings (that aren't Necrotech or have a cell antenna) are all good choices. Anything else is not. Malls, Necrotech buildings, PD's and FD's are targets. Hospitals and Armories are probably the biggest death traps in the game; Armories can't be accessed by Free Running so are seldom heavily barricaded, and badly wounded players often log off in Hospitals hoping for a heal. Zombies are well aware of this.
4. Make sure that your safehouse isn't directly adjacent to any of the targets mentioned above. Zombies aren't stupid.
5. Make sure that your safehouse doesn't have a neon "BRAINZ INSIDE EAT THE HARMANZ" sign on top of it. (i.e., no running generator.) (Alternately, make sure that every building in the suburb has a genny.) Along the same lines, don't place generators in buildings that don't need them. Only cell towers, Necrotech buildings, and Hospitals benefit from generators. You may even want to destroy any generator that you find in your otherwise-perfect safehouse but beware...some folks consider generator killing to be a serious crime, even if it's in a building where it does no good.
6. Check your barricades EVERY DAY. Make sure that they stay at EHB if you're not sleeping in a resource building or an entry point to one. (And if you are, stop sleeping there.) If you find your barricades dropping slightly overnight each day, find out who's doing it and why. If you can't, move.
7. Understand predator/prey relationships. If your EHB non-resource safehouse is located in the middle of a bunch of EHB non-resource buildings and isn't adjacent to something important, chances are that it won't be bothered. Zombies have neither the time nor the AP to rip down the barricades on every single building unless it's a large mob that's making a dedicated effort to wreck the entire suburb. *Do not count on safety in numbers inside the building.* More survivors = louder Groan = more zombies responding. A nearly perfect safehouse will just have you, and maybe one or two other people using it; even if the zombies find out that you're in there, it's just as much work to get into a resource building that will have more occupants and will likely have looser barricades. Which building do you think they'll go after?
8. Never attack a zombie if you don't have the AP/ammo to kill it. Lots of zombies have Scent Trail and may just decide to follow you home afterwards.
9. Budget AP. Plan how many AP you'll need to get to your destination, do what you need to do, and get back home...then add 5-10 to that. Don't count on there being an accessible safehouse at your destination. (There won't be.) Don't count on your safehouse being accessible when you return. (It may not be.) Have a crowbar just in case someone overbarricaded your entry point.
10. Some folks say that hiding in an unbarricaded building is fine, as that will fool the zombies. FALSE. Unless I'm in a hurry I make it a point to check every single unbarricaded building that I pass. I often find zombies already in there as well, so I'm not the only one checking. Sometimes I nab a harman, sometimes I don't, but it only costs 1 AP to check. It's better than being on the street but it doesn't fool the zombies anymore.
11. If you log on to find your safehouse under attack, DON'T PANIC. Chances are that it's either a small group or it just started; otherwise, you'd already be dead. Here's how you handle that:
- Restore the barricades first. The rest of the mob (and any ferals nearby) are on their way. Keep them out. If you don't have Construction, at least close the door.
- Dump any bodies on the ground. It only costs 1 AP to do. Dealing with a newly risen zombie costs a lot more than 1 AP.
- Heal anyone near death. These are the folks that (hopefully) will pick up where you leave off and they'll have to be alive to do that. Remember that it takes a maxed out zombie about 30 AP on average to kill a survivor at full health but it only takes 12 AP to heal one. (Or 6, if you have the right skills.) In a healing/killing race between an equal number of survivors and zombies the survivors will win.
- NOW, start killing the remaining zombies and make sure to dump the bodies immediately. Don't wait. Most zombies love to save a few AP in a big fight to stand up at the end of it before they can be thrown out; it annoys the hell out of the survivors and makes them waste a lot of AP and ammunition.
When you're down to your last few AP, jump to a building next door and hope that it's not already cracked. (If it is, keep looking -- that's why you saved a few AP and not just 1.) If you can't do all of this, do what you can and THEN get out. The other survivors will thank you.
The main thing to remember is that barring a huge seige (with several hundred or more survivors holding the barricades) even a small group of zombies WILL get into your safehouse if they want to and once they're in, they'll call for help. Playing as a zombie is helpful because you get a feel very quickly for how things work and what the best targets are. Make sure that you don't sleep in a target.
Kind of along the same lines, some folks advocate moving your safehouse nightly. I disagree. If you picked the right safehouse it will not be bothered unless the entire suburb is being attacked and it will likely be one of the last buildings to fall. However, don't be afraid to move if you have to.
Although it's somewhat unethical (and really not necessary) the various Urban Dead forums can be great sources of information on what's happening.
Advice for zombie players: eat harmanz. If none are on the streets, proceed to your nearest Hospital, PD, or FD and tear down the barricades. You'll find plenty in there.
Edited to add: Besides Ridleybank and Barrvile (which have been firmly under zombie control for some time) there are several very large zombie hordes actively trashing Malton on a systematic basis and a couple of suburbs are pretty much destroyed. If you're wandering along and suddenly notice a lot of buildings with open doors and zombies in them, go back the way you came. Chances are that the entire 'burb is trashed and you're not going to find a safe place to sleep there. Also keep in mind that when they're done with that neighborhood they'll be moving to a new one and it may be yours -- be ready to move.