Idea for Chess Variant - Promotion Chess

The goal of the game is to have all your uncaptured pawns get promoted.

Some changes to the rules:

• It is possible to have the king captured in the game - however, after the king has been captured, only the unpromoted pawns are allowed to move.
• If one of white's pawns is captured, it means that white only needs to promote 7.

Does that mean that taking the 8th pawn looses instantly?

Not necessarily. If both players take the 8th pawn, then it's a draw.

It sounds like you did not think this through very well, and that you did not understand the question.

What is "the question"?

If I take 8 pawns from you, will you win because you don't need to promote any pawn anymore? Or will I win because you can't promote any pawn anymore?

2nd question: what happens when only unpromoted pawns are left on the board and they block each other? Draw?

I like the idea that getting the king captured does not immediately loose but immobilizes the non-pawns.

What if both sides have lost their king, and their only pawns block each other?

Draw.

If all 8 pawns are taken, the person whose pawns have been taken doesn't win. However, it doesn't also mean an automatic win if a player takes all of the other player's 8 pawns, as the goal of the game is to promote all of your uncaptured pawns.

If the remaining pawns block each other, then it is a draw.

OK I understand, if you take all of your opponents 8 pawns, you still need to promote all of your own uncaptured pawns. If both players take all pawns - 16 captured pawns that is - it should be draw.

This brings about quite counter intuitive playing. For example, my opponent has promoted three pawns and I took four of his pawns. I can't take the last pawn as I would instantly loose.

It sort of reminds me of the judgment needed in a game like Lines of Action. In it, you need to bring all your pieces into contact with each other. Sometimes capturing an opponent's piece is advantageous (by separating their remaining ones), and sometimes it just simplifies your opponent's task.