When i play minecraft, I cant help but put myself into a realistic situation. Something some people call Roleplaying. For me, theres nothing but playing minecraft in a realistic way.
Building a realistic house or cabin, structural support is necessary in caves, and every map has a backstory.
My most build, inspired after watching a few episodes of Buying Alaska, involved a large style log cabin atop a mega tiaga hill overlooking a lake. Huge front window lighting the interior
It was turning out to be a great map. I had found some saddles, horses and armor, some nearby slime chunks, and I even found some potatoes and carrots from a friendly zombie.
I was short on experience though, and still hadnt found a spawner of any sort, and instead of building a huge sightly mob farm, i figured i'd cheat a little and find a spawner.
Made a duplicate map, turned on cheats, and started flying around underground looking for a spawner.
If you caught that, you'd understand i enabled the new snapshot that has the new Spectator mode.
I accidently entered into my real survival map while still playing the snapshot. Didn't really realize it until the next day.
Logged in without the snapshot, just regular 1.7.4 minecraft.
Fun Fact: Playing in a new snapshot, then switching back to 1.7.4 will delete every item on the map, including items in entities, chests, inventory, etc.
If you knew that, great! I didn't. Now, i have a partially completed mansion without furnishing, and zero items. I'm litterally back to punching trees.
So here comes the question. How does one realistically continue playing the map, where every item was deleted? My horse has no armor, no saddle, and there will never be any more of those. All items in chests were deleted (would this be true to items located in unloaded chunks?).
I've since found about 10 diamonds, and I did end up finding a skeleton spawner.
I'll have to travel to the Jungle 1000's of blocks away to find some melons, and the saddles and horse armor will never exist again.
You can open to LAN to enable cheats (only until you quit; they will be disabled again the next time you play) and give yourself your missing items back. Also, as for stuff found in chests, you can delete the chunks around your base using MCEdit and the game will regenerate them; note that only chunks that were loaded will be affected (the game loads chunks out to 10 away from your position, at least in 1.6.4 and lower).
Of course, I'm too careful to have this happen to me; I have a separate profile for my main survival world (saved in a different location from everything else) and I have a backup; and when I want to do something like use spectator mode to show the caves I've explored or make views like this, I make a copy of my world and place it into the other folder. Note that since I'm using mods loading it in any version will mess it up, if not as severely (only a few, if very valuable, mod items and blocks), and you can always use MCEdit to delete messed-up chunks; the terrain in my world is 128 blocks higher than normal so you can imagine what it'd look like walking out to vanilla terrain.
Also, a good way to get XP quickly is to mine Nether quartz, which is how I've gotten XP to enchant my items in the last couple worlds I've made; the Wiki even says this is better than a small mob farm (including spawners; you need to kill 165 hostile mobs to reach level 30, or mine 235 Nether quartz, which I can get in 10-15 minutes). While non-renewable, I don't need any more XP, other than what I get from normal gameplay, after I get everything I need (IMO, nobody should if they choose enchantments carefully and rename items; in my case, "normal gameplay" is as my forum name suggests, caving, which gives you tons of XP from mining and killing mobs, you can even use a highly enchanted pickaxe (one unit per repair at 37 levels each) and be able to keep up with repairs).