Chess on an Infinite Plane (gyrados06 - rychessmaster1)
Q(11,-6) is legal but is not check. Legal moves are binding. Here is the current position, and it's now White to move:
(diagram deleted. See comments below)
Gyrados is being generous, so I'll update board with 16...Q(12,-6)+.
This is illegal. It appears you are moving to check so that will be Q(4,-14)+.
Blue lines indicate the queen's vertical and diagonal lines.
16.Q(-5,3)...Q(12,-6)+
17.K(4,1)...Q(4,-14)+
That's perfectly fine. I prefer a null coordinate when everything else is clear, rather than a blunder from a typo, which can't be taken back.
18.N(4,0)...Q(-11,-14)+
What does it mean that the guard is not affected by check? Can you move it if you are in Check?
Sorry, I forgot to answer your question yesterday...check and checkmating is the same as normal chess - it only applies to the king. The guard moves the same as a king, but otherwise it is the same as any other piece - the guard can be attacked and captured.