From 1.1 With Love
Spawn Switching
By using a on/off wire trigger block you can effectively "open" your bed's wall and invalidate the room it's in, leading you to spawn back at the middle of your world. If you're close enough (wiring only works for 2000 blocks or so) you can just hook up a switch at your spawn that'll change the blocks again and allow you to spawn back at your home base. Otherwise, you might be able to coax a contraption with a statue spawner/pressure plate/lava block to toggle it for you automatically.
This post on the TerrariaOnline forums in particular has an interesting bird-based reset circuit that seems to be fairly popular, but you'll need a bird spawner.
Digging the hard way
From your main base, just dig a hole straight down (the classic "Hellevator", if you will). When you get tired of exploring your caves, just start digging left/right towards your shaft. It'll take a while, but you'll at least probably find some goodies (more caves, ores...) on the way, and getting back will be a lot easier. You can even use a depth meter to align all your "escape routes" to the same depth, so that eventually you can just have one long path across the world that speeds up travel.
Previously, on Terraria...
A trick that worked in 1.0.5 was to start up a multiplayer server and explore with a friend (or just explore with two characters locally), then follow the instructions:
- Build a room with a bed. A room isn't necessarily required, but will keep the other person safe. It's best to put the bed in a corner.
- Set your spawn point to the bed.
- Break the bed and use a mirror. Logging out might work but I don't make any promises.
- Do whatever you need at your spawn point. When you're done, let your friend know.
- Put the bed back down in the exact same spot. This is important.
- Use the mirror again.
If you did it properly, you should travel back to where the bed is. This might not work in 1.0.6, though, and it's only good for exploring together -- if either of you get separated, you'll have to travel back manually.
If you're exploring solo, your only real option is just to take the time to improve the path. Wooden platforms over minor gaps and flattening out bumps will help a lot with horizontal movement, and creating a double shaft with a soft landing area (e.g. water) on one side and a wooden platform tower on the other will make vertical travel easier. Using background walls other than dirt will also stop the enemies from spawning.
Make sure your friend has forwarded the ports that Terraria servers require. There's a short guide on how to do it here.
To summarize:
- Double check your friend's IP (ask him to go to www.whatismyip.com and read off the address to you). IP addresses can change occasionally.
- Double check the port. Your friend is capable of setting it to something non-standard, ask him what it is (standard is 7777).
- Get your friend to log into his router (usually 192.168.0.1 or 192.168.0.0, look it up for his specific router).
- Click on a port-forwarding or NAT menu button.
- Add a rule for Terraria as described in the guide.
Beyond that, you will need to provide more information on errors or your friend's setup before we can determine what could be causing your connection troubles.
Best Answer
Each player spawns his own enemies.
On the server, the spawn rate and the maximum spawns are determined for each player. These have varying values depending on whether it's day or nite, the layer you are in or being in any of the special zones like the Corruption, Dungeon, Meteor or Jungle; not to forget about the Blood Moon...
The harder the time, depth and zone; the harder your adventure.
They don't spawn each X seconds but rather by a chance on each single game tick up to a limit.
The spawn rates and maximum spawns from high to low for the same time and layer depth are
Dungeon, the skeletons must kill you! (not influenced by depth and time)
Blood Moon, it's an invasion... (not influenced by depth)
Jungle, to make it harder than other zones by sending those hornets.
Corruption and Meteor
World, which also covers the Underworld.
Thus, depending on when and where you are you can get different order in the lower three. The trend is that you get more spawns in the night and the middle of the map as you'll see zombies, skeletons and all kind of slimes annoying you on your path...
Please note that you can also influence this yourself, increasing chance by 33% and limit by 50%.
How can I test this out?
Is it really about chances?
This is a hard one given that it's works based on a chance and thus could result in a different outcome. A good example of the chance can be seen when chasing down a dungeon without killing the Skeleton first, you'll see a random amount of skeletons spawn after a random amount of time.
On my first attempt I ran down and took the contests of a chest, on another I got killed by 2 of them.
Do the time, depth and zone really affect the amount of spawns?
This is easy to verify, check the amount of slimes that visit you when you stand still during the day compared to the amount of zombies that hunt you during an invasion or even just the amount of fire balls that annoy you when you are mining a meteorite.
Do we really get more spawns together?
The best way would be to play together with a lot of people to drastically increase the amount of spawned monsters, playing with 8 players together on the same screen should give a noticeable difference against just 1 or 2 players. I've been mining a meteorite with my sister and noticed that we each got separate fire balls hunting both of us and when she died I only saw the half the amount...