A player may declare one of his/her monster zones to be affected by “Ground Collapse.”
If “Imperial Order” is active and negates the effect of “Ground Collapse,” the monster zones affected by “Ground Collapse” may have monsters on them. If “Imperial Order” is later negated or leaves the field, monsters in the affected zones will remain unaffected. However, if those monsters leave the field, new monsters may not be placed on the affected zones as long as “Ground Collapse” is active.