function Xadrez:getPiecesOnTab()
    local black, white = {}, {}
    for x = 0, 7 do
        for y = 0, 7 do
            pos.x, pos.y, pos.z = INITIAL_POS.x, INITIAL_POS.y, INITIAL_POS.z
            pos.x, pos.y = pos.x + x, pos.y + y
            local creature = getTopCreature(pos)
            if(isCreature(creature.uid) and (not isPlayer(creature.uid)))then
                local name = getCreatureName(creature.uid)
                if(self:isPiece(name))then
                    table.insert((name:find("black") and black or white), creature.uid)
                end
            end
        end
    end
    return black, white
end