# What are the minimum required pieces for checkmate in 3d chess?

Assuming the rules of millennium 3d chess, what are the minimum required pieces for checkmate?

I realize this is an extremely difficult question, but in regular (2-dimensional) chess, we have rules of thumb for when two players should draw during the endgame.

A few examples of these kinds of scenarios (in 3d chess) would be much appreciated.

• Have you ever played it? Just curious how you play it...
– user2001
Dec 30, 2014 at 8:36
• @RauanSagit - I just played with my friend for a few times, and we were stuck in a close endgame for about an hour... that's what prompted the question! The rules are in the question's millennium 3d chess link. Jan 23, 2015 at 20:21

The following are minimum involving various pieces:

King + Queen
King + Rook + Any Piece
King + 2 Bishop
King + 2 Knight

This is only the theoretical minimum to actually mate. Whether or not it is possible to force a mate in this situation is a different question. You can see these mates by placing both kings in a corner, one on board 1, and the other on board 3.

Here is the following pieces you can do checkmate with:

King + Queen King + Rook King + 2 Bishops King + 2 Knights King + Knight + Bishop

• Those are the minimal material combinations needed to force mate in standard chess, but are you sure each of them suffices to mate in the particular 3d chess variant asked about in the question?
– ETD
Feb 11, 2015 at 23:19
• I'm not really sure what 3D chess is, but I you have "levels", @ETD Feb 11, 2015 at 23:21