Can the Pawn be promoted to a King?
Funny but yes it is distinctly written out within the rules. Several centuries ago, a chess "loophole" (still common in some chess puzzles) was this rule not stated about which color you promoted into. Therefore, it was possible to promote a White pawn into a Black Knight or something similar. The point might be to give the opponent a tempo or to "block" a key square for them.
I don't have a source to that rule written out, but I'm certain I've seen it written out before. In practical speak, promoting into a Queen, Rook, Knight or Bishop (only of your faction) are your only legal options available within the rules ![]()
https://handbook.fide.com/chapter/E012018
- 3.7.5.1 When a player, having the move, plays a pawn to the rank furthest from its starting position, he must exchange that pawn as part of the same move for a new queen, rook, bishop or knight of the same colour on the intended square of arrival. This is called the square of ‘promotion’.