Statement 1 + Explanation
Blackacre to my children for their lives, then to their children for their lives, then to their children their heirs and assigns.
What the lawyer has created is a life estate in Blackacre to T's children, a successive life estate in Blackacre to T's grandchildren followed by a Fee Simple future interest in T's great-grandchildren. However, the Rule Against Perpetuities would void the interest to T's great-grandchildren, and leave the will creating the successive life estates with a reversionary interest in T's estate.
Why? The rules states that any interest must vest, if at all, within 21 years of a life in being at the time of the instrument. The instrument here is a will, so the time of the instrument is T's death, not when the will was drafted. Next, we need to find every possible person, whether named in the instrument or not, who could, regardless how remote the possibility, affect the instrument. T's children, grandchildren etc. are our possible measuring lives because they control who will take Blackacre. For a measuring life to be valid, it must be a life in being at the time of the interest. For a class, such as children, grandchildren, to be valid measuring lives, it must be a closed class, meaning it would be impossible for another class member to come into existence after the time of the instrument.
In the above example, T's children are a valid measuring life. T's children are a class, so the class must be closed at the time of the instrument for T’s children to be valid measuring lives. Here, the class that is T's children would be closed at the time of the instrument as it is impossible for T to have any children after T dies. So any interest which must vest within 21 years after T's children die is valid. The class that is T's grandchildren is NOT a valid measuring life as T's children are free to reproduce after T dies, meaning the class is not closed at the time of the instrument. Obviously, the same goes for T's great-grandchildren for the same reason.
Now that we know our valid measuring lives, we can see which interests in Blackacre are valid. Obviously, the life estate to T's children is valid as they are the measuring lives. The life estate to T's grandchildren is also valid. Why? Because all of T's grandchildren must be born within 21 years of a measuring life. T's children are our measuring lives, all of T's grandchildren must be born before the last of T's children dies (or, at least be in the womb, which counts as being alive for RAP purposes), meaning their interest would vest within 21 years of a measuring life. T's great-grandchildren's interest is invalidated by the Rule. Why? Because T's grandchildren are free to reproduce after all of T's children have died. It is possible that one of T's grandchildren could have a child more than 21 years after T's last child died, meaning the interest might not vest within 21 years of a life in being.
Statement 2 + Explanation
Orville to Adam for life, then to Adam’s children for life, then to Adam’s grandchildren who survive their parents
Purportedly, Adam has a life estate, Adam’s children have a contingent remainder for life (unless Adam already has children alive, in which case the children alive have a vested remainder subject to open [but that’s a contingent remainder for the purposes of the Rule Against Perpetuities]), and Adam’s grandchildren either have a contingent remainder in fee simple absolute or a vested remainder subject to open in fee simple absolute (this remainder is contingent for two reasons: we don’t know who they are, and they must survive their parents). The gift to the children is okay, because the children will be ascertained when Adam dies. If Adam has more children after the date of this gift, then Adam dies and any other children and grandchildren die, then we might not know whether there will be any grandchildren that survive the “new” child until 21 years after the death of everyone living at the time of the gift. Thus, though the gift to Adam’s children will be okay, the gift to the grandchildren will violate the Rule Against Perpetuities and Orville will have a reversion instead. All in all, after the Rule, you’ll have a life estate in Adam, a life estate in Adam’s children, and a reversion in Orville.
Any help would be greatly appreciated, thanks!