A constitution that has special rules for its amendment is said to be

A constitution that has special rules for its amendment is said to be rigid. This means that the process of amending the constitution is difficult and requires more than just a simple majority vote in the legislature. The purpose of having special rules for amendment is to protect the constitution from being easily changed by those in power, and to ensure that any changes made reflect the will of the people and the nation as a whole. This often involves requiring a supermajority vote, a national referendum, or other specific requirements in order to amend the constitution. Rigid constitutions are often found in federal systems where there is a need to balance the powers of the central government with those of the states or regions.