Multidimensions

The dimensions themselves, I do not desire to spoil in their entirety. Upon joining the world, you will be given an item that acts as a guide for the basics of the addon. 

Dimensions are only accessible after killing the ender dragon. In some manner, this should make it so you do not immediately jump into foreign territory. 

Certain armors and custom ores are only gained via progression. In your effort to progress through each individual dimension, through your pain-staking efforts, you will be variously rewarded. Bosses, at the moment, have no actual rewards. The "rewards" currently come in the form of armors and loot. Bosses are fairly linear. Cheating is possible, but it is more practical to catch the hint of playing "fairly", approaching the bosses as one would their first time to any.

Find a knight within the overworld, kill it, and you will gain an interdimensional key. In the key forger all players get upon the ender dragon's death, you can craft igniters and artifacts.

Savepoints are small, star-like checkpoints you can find that activate "keepInventory". Should you touch one, you will be brought back to the location you touched it every time you die. They appear outside/inside boss structures. This is to keep things "fair", maybe easy. I know it would be frustrating to have already dealt with the ender dragon, maybe the wither, and to expect players not to throw a tantrum when the bosses of each dimension demand their attention without anger. (And, hey, for bosses, I'd stack up on golden apples. Enchanted golden apples for final bosses especially.)

Sometimes, the addon can be janky. Expect it to be.

All dimensions have ores, food sources, mobs, bosses, dungeons, caves, foliage, structures, etc... All unique to their respective realms. Dig down if you're looking for the caves.

Here are the eight dimensions:

• The Ruined Wastes
  Simple, honestly. A bunch of ruins. You can find cities, and dangerously saturated messes of foliage. Should be easy to survive in.

<figure class="image image_resized"></figure>

• The Skylands
  In the name. A pseudo Aether, if you will. Though, pretty alien to the aether. Ores are a little tricky here, and you will hate harpies.

<figure class="image image_resized"></figure>

• The Evergoing Caverns
  Useful for mining, but one wrong move spells disaster. A mediocre environment, lacking in life.

<figure class="image image_resized"></figure>

• The Templar's Desert
  If you hate sand, then uh... Yeah, I don't know where I was going that. It's just ruined ancient egypt for as far as the eye can see. Watch out for dust devils.

<figure class="image image_resized"></figure>

• The Nuclear Lands
  Green Fallout by Bethesda. A bit cheaper in terms of resources. It's bleak here. There are cities, but they don't even have lights. I hate it here. At least there are labs. Sometimes.

<figure class="image image_resized"></figure>

• The Algids
  Everlong winter. Ash gives way for some undead. A rapture has emptied the cabins. A dead god waits for you.

<figure class="image"></figure>

• The Deep-Dark
  The belly of a beast. It has consumed countless cities. The only way out is through the Trojan Horse. Kill the ancient warden inside, and you may leave.

<figure class="image image_resized"></figure>

• The SummerSet
  The farlands end here. This is your final frontier, where the three final bosses lay.
   

<figure class="image image_resized"></figure>

The boss structures will call out to you by a beacon and a hint at how far away you are from them. Keep in mind it is an unstable method of generation. But, it works nonetheless. Be careful not to clip inside too early.

CONCLUSION - 
Have fun.

v57 came out, and it basically moves everything over to a new systems with scripts for optimization.