Experience handling estate law, he's yet to see a judge/magistrate overturn the wishes of deceased if it was clearly explained in context. 
 

eg; inheritors continually harrassed, emotionally abused threatened them etc, abandoned and cut off all contact for ages, went no contact when parent was elderly who was left to fend for themselves or another child had to do the caring etc.

there have been cases in Australia where 1 deceased completely wrote off 1 child, because they cut off all contact and completely abandoned them whilst the daughter took on the carer role, sacrificed her career/study opportunities to care for said elderly parent and financially took care of them.

that parent put in will clearly why he willed the house to her and financial reimbursement for her sacrifices. Son claimed he was dependent on the money bit was a dead beat into drugs etc. judge still honoured deceased wishes that property go solely to daughter.

Lawyer will explain to you what should be worded better or what justification for things and what could be challenged in court and how to circumvent that so it can't be challenged etc.

my dads lawyer said all the illegal shenanigans of my brother handling my mums estate, keep that separate and nowhere mentioned in dads will the money he stole, benefitted and profited off at my expense. My brother threatened to take me to court if he never got 50-50 yet my mums estate overseas which follows shariah law where man gets 2/3 and woman 1/3 despite making an agreement with me to go 50-50, still went in secret and took 2/3 which is illegal under aussie law and i could suit him in australia but chose not to because its such a headache dealing with him as he and his wife are hell bend on delay tactics and disinheriting me and playing innocent victims to extended family and making lies up which i could take him to court for defamation and in my husbands country where mums largest estate is, my brother would be thrown in jail.

As a fellow Australian, I was thinking the same thing. It's virtually impossible here to leave out a biological child from your will - they can contest it and, in most cases, win. I am sure though there is ways to do it with trusts etc. 

In fact, every state has different laws regarding wills and inheritance. That's why we did everything with a licensed attorney and it's filed with the local Clerk of Court's office. 

or inheritance law. My dad visited a lawyer to clarify this 5 yrs ago for this exact reason. My brother basically abandoned him and my elderly mum and went no contact for over a decade as an elderly man and i took responsibility for dad and mother and cared for them, handled majority of all household bills at dads home which has always been in his name not even my mum was added as co owner as dad bought this before marrying my mum and they were married 26 yrs till divorce.

I even got on next flight out from overseas when my dad had to get emergency surgery as was extremely ill and my brother refused to answer any calls emails despite living 15 mins away.

what was explained by the lawyer in will is if there is an unequal division, there needs to be context. If the deceased put down this person has maintained no contact and disowned me whilsty spouse or other child maintained a strong relationship with me and cared for me financially etc and thats why i will my assets to her solely or largely to her etc, a judge will honour it

the only way that alienated child or whatever can attempt to challenge is if they claim they're financially dependent on their elderly dads money. They can't prove that if an adult and have not maintained a relationship with that parent in decades. If there is context of why unequal split, a judge will not go against a will. 
Also lets say there is a difference in ages where dd is a minor, son is an adult, the father can explain i leave 60-70% of my estate to my daughter so that she will have basic expenses provided for till adulthood as i provided for my son previously. How can the son challenge that? Its explained logically for a judge. 
 

there must be an explanation and logic in every explanation. This sense of entitlement that you can abandon a relationship with a parent for decades and when they die scream that your entitled to their estate because now your family is the reason why some retirees spend their life savings and sell the home and travel the world so kids get nothing of what they worked hard for.
 

a way to bypass a greedy shameful inheritor claiming they deserve 50-50 etc, is to add the spouse or child you want assets to remain with is to add them as co-owner as this does not form part of deceased estate and cannot be challenged in court and automatically becomes that co-owners property upon the others death. Same thing with bank acct and savings is havenit in joint names with spouse so it becomes their money upon the others death etc.

if this isn't done and the alienated child or child who essentially disowned their parent wants to challenge the unequal aplit in court, they can ask the magistrate to have deceased estate pay for their legal fees. Magistrate won't honour this if no case

as far as lawyer in australia explained is its unheard of a judge going against a will that has provided clear context and reasons for an unequal split. If deceased intends to leave nothing to their kid, its easier to add their spouse or other child as co owner of their home and bank acct etc as they can't be taken to court, its 100% legally their asset and not estate stuff.

i am currently dealing with this with my brother who cut off contact with my elderly dad over a decade ago, them when mum died sneakily took all assets and depositednit from 2 countries into he and his wifes joint bank acct and later their offset acct to keep their mortgage lower (100% illegal in Australia)

when my mum died, my brothers wife had told him to disown me from my parents estate, and do everything possible to keep funds away from me. He has managed the estate unethically and illegally and refused to answer me which he is required to by law with regards to estate matters. 
 

my brother and his wife harrassed me and my husband stating i was entitled to 0% when i have been the only person caring form my elderly dad and frequently in contact with him. Its gotten to such a point where my dad requested himself to add me as co owner on his home because he wants nothing to go to my son. I have to pay the stamp duty etc associated with my half share in the house and when he dies, the house automatically becomes mine.

my brother can't take me to court for half share or claim half of dads share in the home as dads share according to aussie law becomes mine upon his death.  
if my brother finds out before dad dies that i am co owner he can't even be successful in court challenging dad adding me as co owner as my dad is free to transfer whatever assets he deems. 
 

you can't decide your not family when alive and upon death be a greedy pig and claim about inheritance rights etc when you realise you don't get 50-50. A judge will look at the whole situation in context and its very important for a will to explain things and the lawyer will advise this to and how things should be worded so it cannot be challenged. 
 

a judge won't willy nilly go against a deceased will if there is clear context and explanation for it in cases of an unequal split. Also a judge won't look kindly to say a greedy son who has maintained no relationship or contact in decades and abandoned said parent now claiming upon their death that they're entitled and dependent on their late deceased parent's wealth.

 But to circumvent estate money being used for the greedy deceased family members suddenly claiming they're entitled inheritors etc, you need to make it not part of estate so adding co-owners for property, joint bank accts etc does that 

the will also needs to state who the executor is so money isn't being wasted applying for probate etc because the assets forming part of estate will be minimal and not required in australian law