Why can't you promote a pawn to king?

Not pawns..... but the little guys all over the board.... All of em'

@egoole - If you're seeing little guys all over the board, I think you should take a break for a little while and get some rest.  

I have just updated the OP/original text, because obviously I had not thought it through enough.

Now that you've edited it, all of a sudden this looks like an interesting variant. I'll love to try it, but standard chess can't really be replaced by this variant.

It won't change anything in practice. Under-promotion to King would as common as promotion to Rook, even if you play by rules that both Kings need to be captured before you lose.

Back in the 1970s I discovered that you could set up a position on the primitive Boris chess machine with an extra king on one side; Boris would accept this setting, and then, if the other side managed a discovery or a fork that put both those kings in check at once, it interpreted that as checkmate and the end of the game, because there would still be a king left in check even if either check by itself could easily be parried.

You sure? It's a different paradigm than a rook or minor piece, because unlike those, extra kings give you more chances to survive. I'd be lying if I told you I think this is a really fantastic idea, or even a scarcely acceptable one.  More an idle curiousity.  But it is fun to toy with the idea, in spite of it going nowhere fast.

Lol, couldn't have said it better myself. 

Promoting to Queen, however, does not only give you more chances to survive, but gives the opponent very much less chance to survive. The extra King would not be very dangerous as an attacking piece, due to its slow pace. From Spartan Chess we know that the extra King is worth less than a Rook, in general.

But what if your king is pinned in the opposite side of the board and close to mate. You can advance a pawn, yet getting the queen can have no effect on that attack, but getting the king saves you, while you perhaps promote another pawn or whatever. Probably wouldn't be used much, but I can't anticipate far enough ahead to know.

Hey @nimzobogo,  In my defense I will say, I wasn't planning on creating yet another thread at this point, but someone dredged this one up from two years ago.  Also, WTF, man, who cares?  What were the important things you wanted to talk about? Make we can get some U.N. members in here to make it happen.

They would fight each other

Although this looks great to me (and you probably) it can't realistically be implemented.

Sure. It can happen. Promotion to Rook can be needed too, in exceptional situations.

What you describe is pretty exceptional too. I have seen it happen only once, in Spartan Chess.

Only Chuck Norris promotes his pawns to Kings

because the box only comes with one black king and one white king. Y'all know the box ain't ikea - when somethang is always left over, so the idea is off like a herd of turtles.

Queens are eunichs, and.............never mind!!!!

Why can't a pawn be promoted to a pawn?

If rules were made to prohibit capture of a 1st or 8th rank pawn, it could be used to block off access to a key square.

-or- What if you were allowed to promote a pawn to pawn at the 8th rank, and it would wrap around in its file and attack two diagnonals from it on the the 1st rank and could move forward to to the first rank if not attacking.

In the "Extinction Chess" variant you can promote to a king. You can have up to 8 kings on the board at once if you like, but reducing yourself to a single pawn is generally a very bad idea.