Tutorials/Ultra hardcore survival

Are you ready for an even harder challenge than Hardcore mode? Well then, meet Ultra Hardcore! In Ultra Hardcore mode, the only difference to the regular Hardcore is that you don't naturally regenerate health! This difficulty is extreme, so it is advised to try hardcore mode first to gain extensive experience, and move on to this difficulty when you think you are ready.

All the rules of regular Hardcore still apply, read them first.

To play on Ultra Hardcore, you must first create a Hardcore world. Once the world has finished generating, open the pause menu, click the open to LAN option, and turn on the allow Cheats option, before clicking the "Start LAN World" button. Once this is done, exit the menu and enter the following command into the chatbox: /gamerule naturalRegeneration false. Once you have completed these steps, save and exit to the title screen, before returning to the game. Now you have successfully created your own Ultra Hardcore world.

Notes and Tips

First of all, as stated before, there is no natural health regeneration. So remember to avoid even the most pathetic ways of getting damaged, like cacti, or it's all over.
You'll have to be really quick with getting resources because danger is doubled always with no regeneration.
Regeneration is crucial. You can regenerate health only with Golden Apples and potions.
You can make a Golden Apple or a Potion of Regeneration/Healing (Preferably Tier IIs)
Although hard and labor-intensive to acquire, a beacon can significantly make your life easier, along with reducing the amounts of potions and apples you may consume.
Remember hunger is the most crucial part of survival. As with a normal survival, get food quickly. Hunger is a pitiful excuse for taking damage.
Keep a water bucket on your hotbar at all times. Fire damage can be minimized by using a water bucket.

Tips that apply to PvP

If playing extremely competitively, consider trying not to earn Taking Inventory before punching wood, so you can hide your achievements and prevent enemies from seeing your progress.
A great way to check out if there are any players in the vicinity is to trap yourself in a small capsule. The lack of lighting causes everything to be dark except for name tags, which are now more visible than regularly.
Gold and apples are going to be your top priorities. Apples can be found on the surface and dropped from oak leaves, like saplings. In many cases you'll have more apples than gold.
While waiting for your items to smelt, consider farming Gravel to gain enough Flint to craft Arrows.
Consider checking out YouTubers or Twitch streamers to see their UHC strategies.
The game usually goes up to 1-2 hours, so make sure you won't starve (in real life) or go to restroom, keep some water beside you and snack if necessary.
Check the rules before going into a game of UHC, some may have player head apple and strength/regen disabled, you might just want to read it before joining.

Beginning

There are a lot of options of what you can do play singleplayer UHC, but if you want to survive, you generally want to either not take much damage, or get a lot of materials to heal with. Generally you want to start by getting some wood and stone tools like usual, and it's generally recommended to get a full set of iron armor before doing anything else, although it is not really necessary, especially if you are good at avoiding taking damage. It is also generally good to look for chickens for feathers for arrows before you start making skeleton grinders. Also it might be worth it to try to get apples (for golden apples for healing) or leather and sugarcane (for making enchantments). This is probably a good time at which to hunt spiders for string if you want, although remember you can also get bows from skeletons and in caves. Try to avoid taking damage as much as you can, especially if you are not full iron yet.

Next you should probably either continue more caving or go to the nether. Since this is a singleplayer world you probably want to do both.

Caving

Caving in UHC mode is what you make it. Generally people either try to go super fast or super slow. The goal of going super fast is to beat mob spawns through the caves and gain materials more efficiently. You can light behind you with torches if you want, especially if you plan to go back out the way you entered. If you run through placing torches you might want to not even mine ores to get through faster. The other approach is to go through caves very slowly. A lot of people will recommend this, although for competitive or time based environments just running through is generally more efficient for getting materials. When caving slowly, always block off mobs and attack their feet.

The Nether

Read the Nether survival guide first.

In general, avoid all types of damage. However, you must be even more cautious due to the many dangers in the Nether.

Lava is way too easy to fall into, and with no regeneration, you will die quickly. Brew a Fire Resistance potion if you are going to be in the Nether for a long time.
If you are not looking, you can walk directly into fire, which never burns out on Netherrack.
Be watchful for sharp drops, and never dig down. Many floors are only one block thick, with the sea of lava directly underneath.
Ghasts can quickly kill you, as well as blow out your portal. Surround your portal with cobblestone, and listen for their noises.

In a pinch, smelt netherrack into nether brick. It will not be destroyed by Ghast fireballs.

The End

The End is essentially the final stage. You need to kill the Ender Dragon, so increase your chances before you enter.

Bring a sword, preferably diamond. If it is low on durability, bring a backup or repair it with an Anvil.
Enchant your sword, bow, and armor. Armor is especially important; go for Protection IV

A Level 1 enchant on a bow guarantees Power 1.

Never attempt to destroy the Ender crystals by melee attack. Use Arrows.
Bring snowballs. Either find the right biome or get a Snow Golem to farm them. These can break Ender Crystals that heal the dragon.
Entering the End can be very dangerous as players can spawn on an obsidian platform which floats above the void. This leaves players very vulnerable to being knocked into the void by the Enderdragon. To reduce this risk keep an enderpearl on your hotbar while entering the end so that you can teleport off the platform. Remember that when you do this you will also take enderpearl damage.
If you don't want to fight Endermen, wear a pumpkin, however it will block your vision. Many players opt for a helmet and simply use a bucket of water to get rid of aggressive Endermen.

Another method is to wear a pumpkin in your helmet slot and then press F1, as this hides the pumpkin face. Alternatively, players can use a resource pack to make the pumpkin face texture transparent.