On the death of a person, his/her assets are distributed amongst the persons as specified in the will. However, in case a person who dies without leaving a will (i.e. he dies intestate), in such cases the assets would be distributed according to the law based on his/her religion.

The succession of Hindu, Jain, Buddhist and Sikh is governed by the Hindu Succession Act. Muslim succession is governed by the Muslim Law and Christians are governed by the Indian Succession Act.

For e.g. Intestate Succession in case of death of a Male Hindu.

In case a Hindu male dies intestate, i.e. without making a will, his assets shall be distributed according to the Hindu Succession Act and the property is transferred to the legal heirs of the deceased.

The legal heirs are further classified into two classes - class I and class II.

Class I heirs consist of the immediate family linked by the male. It includes wife, son, daughter and mother. All the people in this class shall equally divide the share among themselves.

For better understanding of class I heirs, refer to the chart given below:

In case of absence of the class I heirs, the class II heirs will become entitled to the property of the deceased, Class II shall include other family members including extended family members. If even one class I hire is available then the assets shall be transferred to that person.

Conclusion:

By writing a Will, a person can bypass the above succession law and bequeath his assets as per his Wish.
For example: He can bequeath 100% of his assets to his Wife