"Per stirpes," "by representation," and "per capita at each generation" are all descriptors that tell the reader how to allocate a gift among a person's descendants. They are not shorthand for contingent beneficiary provisions. (While this discussion applies to all three, I will use per stirpes for the rest of this blog.)
The Good: It's easy.
To use per stirpes correctly, you just have to follow one rule: Always make the gift to a person's descendants, like "to [person's] descendants, per stirpes." Note a couple of things: (1) in general, the person should be one person, not a class of people; and (2) the word "descendants" (or "issue") must always appear. Here are some examples:
-- to my descendants, per stirpes.
-- to John Dough's descendants, per stirpes.
-- to my mother's descendants, per stirpes.
The gift is allocated to the person's descendants according to the definition of per stirpes, which appears in all ElderDocx® wills and trusts. If you keep it that simple, you won't mess it up.
The Bad: It gets messed up all the time.
Think about that last example above. If I have no children, I might be tempted to take a shortcut and write something like, "to my brothers and sisters, per stirpes." It sounds more succinct and clearer than "to my mother's descendants, per stirpes"—which requires the reader to engage in some mental gymnastics by going up one generation to my mother, then back down to her descendants, and then to know that I have no descendants, finally to realize that I'm talking about my brothers and sisters and their descendants—but it's just plain wrong.
And thinking that it works is likely the result of the single most common misunderstanding about per stirpes: that it's shorthand for contingent beneficiary provisions. It's not. Instead, it's a descriptor about how to allocate a gift among a single kind of class of beneficiaries—descendants. You can't use per stirpes with any other class of beneficiaries—not children, nor brothers and sisters—only descendants. That's why the word "descendants" must always appear. The gift is to someone's descendants, and the descriptor merely says how it's allocated among those descendants.
And don't let the fact that my children are my descendants confuse you. My children are merely a subset of my descendants (well, hopefully, someday). The word "children" does not have the same meaning as the word "descendants."
Another point of confusion is that if the ancestor's children are all living, then per stirpes will allocate nothing to more remote descendants. For example, if I say "to my descendants, per stirpes," and if I have 3 children, 9 grandchildren, and 27 great-grandchildren, I have a total of 39 descendants. And if my 3 children are all living at my death, then they are the only ones who receive anything, and my 36 other descendants get nothing. This, I think, is another reason people want to say "to my children, per stirpes" (which, of course, does not work).
I probably don't need to say it, but thinking that per stirpes is shorthand for contingent beneficiary provisions can also lead to the abomination, "to my son, Peter Dough, per stirpes."
Finally, some want to write "to my then-living descendants, per stirpes." After all, we're not going to give anything to a deceased person, so why not say "then-living"? Answer: because it's at best duplicative and at worst creates an ambiguity. The definition of per stirpes assumes that some descendants will be deceased, so limiting the class to "then-living" descendants might create a problem. Just keep it simple as described in "The Good" and don't embellish.
The Ugly: It can get worse.
When the writer uses per stirpes incorrectly together with another descriptor that is used correctly, then it starts to look pretty bad. For example, it works to write "to my children in equal shares." I have a gift to a class of beneficiaries—children—and I want them to get equal shares. Simple enough, but what if a child has predeceased and I want the share to stay in that child's family line? The temptation for some—present company excluded, I'm sure—is to write "to my children in equal shares, per stirpes." Of course, this comes from the misunderstanding that per stirpes is shorthand for contingent beneficiary provisions, which we know it is not.
While that's plenty ugly, what's really ugly is the court fight between the predeceased child's children and their aunts and uncles. Don't find your documents on display in a courtroom. Just follow the simple rule outlined in "The Good."
As it relates to the "one person" rule, we cheat a bit in the ElderDocx joint trusts where we say "to our descendants, per stirpes." In the document, we define "our children" as those children listed in the trust, and we define "our descendants" as those children and their descendants. While it violates the general admonition to limit the ancestor to one person, we think it works in the context of a joint trust.