This should be a simple question... I guess I will see. If a person draws a will (and trust) and; omits one of his children in the will, Does not mention the child's name anywhere in the will. Does that child have the ability to contest the will?
Yes, an omitted child may be entitled to a share, depending on the circumstances. See CA Probate Code Sections 21620 et seq.
You can contest the will. First you must standing, that is, the omitted child. Then you need a ground to challenge. The testator's capacity is a basis. Mistake, fraud, or undue influence will be grounds.