How much is a king worth?

The king is worth infinite points because if you lose it, you lose the game. However, I'm asking from a piece movement point of view, if you had a piece that moved like a king but could be captured, how much would it be worth? I'm thinking it would be weak in the opening but powerful in the endgame. Also I'm pretty sure it can be used to force mate against a lone king

It's 3 (give or take, sometimes its 4) in the endgame.

4 pts according to some computer programs and Dr Lasker. Surprised? I was, because many older works list the King as being worth about 2 pawns, but this is apparently too low. If you're only thinking about the King being weak in the opening and strong in endgames you need to start working on basic endgame principles until you're absolutely sure about this and many other important endgame concepts.  http://blog.chess.com/NimzoRoy/endgame-faqs

 https://en.wikipedia.org/wiki/Chess_piece_relative_value

Rule 9: The King is a strong piece - use it! - 15 Rules for the Endgame, BCE

Depends on its position... a poorly positioned king is crap, and a centralized one supporting its pawns is very powerful indeed.

Can this piece give check?

I suspect a 'normal' king plus this piece will be able to force mate?

I look at it this way, it would be worth at least a shark without lasers, or to be more clear, it would be worth a yak.

We're reffering to the king's relative value in an endgame, not a seperate piece in a variant of chess.

Funny how I made almost exactly the same topic about a week ago:

http://www.chess.com/forum/view/general/value-of-king-like-piece

I made that topic too, only a long time ago:

http://www.chess.com/forum/view/general/value-for-the-king

I'll bump your threads, ajmeroski and VULPES_VULPES. You just can't have too many threads like this

can you promote a pawn to a second king...?

Yes. That is why double-check is so scary.

Not legally. You might like checkers instead because in that game there is no choice in what checkers promote to - they can only promote to a King.

Is that like a double dog dare?

I would say that it would be worth no more than a 3,  because in the opening and middle game it would suck horribly, and in the end game, its not that much more powerful than a bishope

If the king is worth 4 pts movement-wise, then a "fake" king would be harassed in the opening and middle game by minor pieces, so you would also have to somewhat hide this piece. I find that very interesting because it means the king's movement fits very well with its role as the achilles' heel.

A king is worth 1,000,000,000,000,000

How many lightsabers does the yak have?

I've read that the combat value is about 4.

That's an excellent question, FancyKnight! There doesn't seem to be much evidence that yaks carry sabers, so I don't know if they were light or heavy.