I know that there have been many regeneration suggestions already . I'm posting this one as, though it has some things in common with Arcphoenix's idea (https://swdteam.com/forum?p=thread&tid=527), the point is actually different.

IMPORTANCE (why is it worth doing?)

Regeneration is one of the most famous and unique processesin the whole Doctor Who universe. I am sure that it also is the most wanted feature and would be a very great improvement if performed good.

TRIGGERING REGENERATION

Regeneration can be triggered either on the player's free will or while he is dying but not dead yet (1/2 heart). The player should be able to cancel the regeneration in the first stage by pressing R (watch Regeneration process paragraph)

REGENERATION PROCESS

The process itself should consist of four stages:

• Pre-regeneration state
• Regeneration itself
• Change
• Post-regeneration state

1. PRE-REGENERATION STATE

This is the beggining of every regeneration, in which the timelord prepares for the process.

In the show:

  The hands and the face of the timelord start to glow yellow  (it begins from the veins), emit regeneration particles

The timelord's sight might become darker and sometimes he can see spinning hallucinations of himself or his friends:

How to perform in the game:

If the player has 1/2 heart, this stage begins. It also can be enabled by pressing R. It should last 5-15 seconds (random).
If the player doesn't want to regenerate, during this part he can press R and the regeneration will stop.

Effects:

1) The screen becomes a bit yellow

2) In a small chance, he sees images of himself spinning in front of him:

If you can't code that, just use the MobAppearance effect (might be a bit realistic)

3) The player gets absorption effect till the end of the stage.

(He gets extra 8 golden hearts so that he can live if he was dying. He can still be killed, then regeneration will stop)

4) The hands and the head f the player start emitting lots of slow, but concentrated particles:

2. REGENERATION

I don't think that anyone here need explaining what regeneration is. In the modern episodes, regeneration is usually followed by powerful flow of regeneration particles and furious bursts of destructive energy, strong enough to blow up the TARDIS or a huge Dalek Ship. 

How to perform in the game:

Regeneration itself starts after 5-15 seconds of the 1st stage. The particles mentioned in the previous part remain, but their speed increases greatly. The player gets slowness  (so that he can't move) and (hard to guess) regeneration effects:

Types of regeneration:

Regeneration can go in 2 ways: normal and destructive. The consequences of it depend on the type. In the game the type is chosen randomly.

Normal:

In the series, normal regenerations have been shown in classical episodes and in 8th, Warior's, 9th and 10th (1st) regenerations. In this kind of regeneration, regeneration particles appear and the timelord just heals himself and changes his body without any damage to the surrounding world.

In game: the player emits particles and light, then changes into the new form.

Destructive:

10th (2nd), 11th regenerations are the clear examples of the type. The emitted energy can destroy almost everything.

In game: the sides of the player emit bursts of energy, followed by regeneration (named before) particles and explosion ones:

If the mobs/players are close to the player, they get seriously hurt by the regeneration (mentioned before) particles.  The player is not able to move (due to strong slowness effect), though he can hit others. The player can send regeneration energy streams to any direction, in which all flammable blocks, dirt or stone start burning. Players and mobs, who get hit by the stream, get severely damaged (>10 hearts). Streams are also followed by explosion particles.

3. CHANGE

This is the most important part of my idea. The game should have some player skins, in which you can regenerate. The skin remains till the next regeneration and loads with the game. The game should have Steve, Alex, and some well-known popular skins like those (just an example):

The skins must be basic (not thematic). The picture is just an example (ignore the nudist, etc, didn't mean anything, just didn't find anything proper, sorry). Doctor Who related skins shouldn't be there and might be sold in the shop like the hats currently are.  While regenerating on Gallifrey (when added), the players will be able to choose apopearance.

Beta testers and donators might have an option do upload 3 of  their skins to the site. Then, in a high chance they would be able to appear to them only.

4. POST-REGENERATION STATE

In the show: 

This is the state a Timelord enters after the regeneration, it might be a few minutes or a few days long. Depending on the regeneration, it can make the timelord to loose consciousness and faint, or just leaves some of his sences unfunctional. Doctor sometimes said that it had been a reset of everything while the state.

During the state, the timelord releases regeneration particles from his mouth. He also has some energy to heal himself and even to grow parts of his body.

In the game:

After the regeneration Player randomly gets various effects such as:

• Nausea (50% chance)
• Speed/Slowness (30% chance)
• Haste (20% chance)
• Strength/Weakness (30% chance)
• Jump boost (20% chance)
• Regeneration/Resistance (20% chance)
• Blindness/Night vision (30% chance)
• Hunger (10% chance)

The player might also loose memory (forget what he did). That will be shown as he will be teleported to a random place from nearby.

The post-regeneration state ends when the player sleeps in the bed. He can also make it quicker by building in the TARDIS dimention ("Redecoration")

I'm sorry but this idea took a great deal of time. I haven't managed to finish everything. I promise to finish it within a few days. Post-regeneration state and other parts are still to come

Also, does any1 know how to fix the images? I had it ok in the thread editor:

After saving one, it just looks wrong:

This sounds like a pretty cool feature and I would love to see it added to the mod, I do have a question though. Once the player has regenerated, will he/she be able to reset back to their normal skin?

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Actually, Second's doctor's regeneration was a bit different. He was attacked by scarecrows sent by the Time Lords during season 6B.

Thanks for the mention by the way

I love this feature. By the way i think that it would be great to add some doctor who related skins,not all of the skins should be doctor who but some should be doctor who.    

 I mean the regeneration from the show. The way it is visualised.

This is a amazing idea and should really be put into the game but dont you think all the particls could cause some issues with people who have bad compturs like me my self i have like the worst kind and all these particls will most likely get me to around 0-1 frame im not trying to  say that the whole thing should be done is a different way but just in a way with less particals 

THE THREAD HAS BEEN UPDATED

YAY xD LOVE THE MEME!!

I love this idea. But one question. How did you get my skin!?

 That is probly a picture off the internet and it says that in the thing if you would have read it

 ...Sorry I did read it but I wasn't thinking when I posted that. xD

 That might depend on the player, but I don't think that will be fair. The players might upload their skins to the Web, and, as I've said, they would be regenerated into in a high chance