and experts estimate that about 60% of Scots have not written a will.
But if you die without making a legally valid will, your loved ones could end up with nothing.
Will Aid, which runs throughout November, is a good opportunity to write a will as a participating solicitor will waive its usual fee and the money will instead be donated to the nine Will Aid charities.
You can find out more about the scheme, as well as the solicitors involved, at www.willaid.org.uk.
Allan Crocker, a partner at Scottish solicitors Lindsays, says: "A will allows you to appoint an executor and to create clarity and certainty for your surviving relatives and friends.
"There can be horrific legal and emotional complications if you die intestate, which can be very distressing for the survivors."
If you die without a will, the laws of intestacy will determine who gets what.
A surviving spouse, for example, would have so-called prior rights on the matrimonial home, its contents and any cash, up to a certain value.
If the estate is modest, it is not uncommon for the prior rights to exhaust the funds, so any children would get nothing. It's also wise to bear in mind that a spouse includes a civil partner, but not a cohabitant.
James Brogan, senior solicitor at Russel + Aitken says: "The laws of intestacy can be quite brutal. For example, a cohabitant has no automatic rights to your estate, even if you have been together for many years.
"In other words, your home, its contents and any other assets could go to some distant relative in a far flung corner of the world."
A cohabitant can make a claim through the courts, but it must be initiated within six months of the date of death.
Brogan says: "Modern families can be quite complex, which makes a will all the more important. If you have been married more than once, have children from a previous relationship, or if you live together but are not married, a will is essential."
A will allows you to clearly set out who you want to benefit from your estate. Perhaps you would like to leave your property to your children, or some money to your nieces and nephews. If you have young children, you can also nominate in your will a legal guardian in case you die before they have grown up.
The age of inheritance is Scotland is 16, so you might want also want to set up some kind of trust so that your children cannot get their hands on any money until they are 18 or even 21. You will need to appoint an executor who will sort out your estate when you die, so it's important to name someone you can trust with the responsibility.
The executor can be a beneficiary, but does not have to be your next of kin. If no executor is appointed, then an application must be made to the court, which can be costly and time consuming.
Your will should be signed in front of a witness, who must be totally independent.
Unlike executors, witnesses cannot be beneficiaries of the will. You should then keep your will safe - and tell you executor where it is stored.
Experts recommend that you review your will at least every five years. Crocker says: "It's important to keep a will up to date.
"You might want to make changes if, for example, one of your main beneficiaries dies, or if there is a change in your financial or personal circumstances, perhaps if you have children or buy another property."
It is perfectly legal to write your own will, but most people prefer to seek professional advice, particularly if their affairs are not straightforward.
A solicitor should also be able to help you mitigate any liability for inheritance tax. Many people these days also want advice on how to minimise future care costs.