Using Book of the Estate, we have 1-2 death chance on 1d20 until 8 and 2.5% after that until 21. Maintenance doesn't matter until you hit Famine, Pestilence or Plague, so that simplifies things. We assume a peaceful, plentiful land etc.

The probability of child survival until 8: 47.8%
The probability of child survival until 16: 39.1%
The probability of child survival until 20: 34.4%

So we can see from the above that about 4 in 10 girls survive long enough to get married, and about 1 in 3 boys survive to be knighted... Those are pretty depressing numbers, especially when you consider that the typical wife has around 3-4 children during her lifetime (using Greg's new childbirth tables, unmodified). Again, this puts you below sustainability as far as the species are concerned, even without having disturbances, wars, famine... And these people are the nobility! One shudders to think of the death toll amongst the peasantry!

The problem is that you keep rolling each year, so even a small probability becomes cumulative. If you have 10% chance of snuffing it, you have 50/50 chance to make it to your 8th year. That is not really ideal.

Given that pretty much the whole point in Pendragon is to play a family line, do we really wish to make it this hard? Having the default PK to be a vassal knight (which looks like to be a Rich lifestyle to my eye) helps a bit, but the child survival roll is the true bottleneck, and as Rules are at this stage, the maintenance doesn't help child survival.

So, how to 'fix' the child survival? Well, lets start by halving all probabilities across the board and see how that goes?

1-7: 5% chance per year => 70% survive this stage instead of 50% as before, an improvement of 40%.
8-20: 1.25% chance per year => 59% of the starting population survive to be 20, instead of about 34%.

Together with the adjusted childbirth table (see the Women's survival thread), we'd now get a median children surviving to be adults per woman to be about: 5*0.6 = 3 children per woman. Hooray, we have saved the species!

This means there will be more surviving children which means more dynastic play (with spares) which means much more fun for the players (and money sinks to siphon off the excess loot). All good things in my book.

Should the grade of maintenance influence the survival of the kids? Sure, why not. It is a bit more difficult to do, but lets say that the Rich would take 20% off the death chance, and Superlative 40%. So the probabilities become:

Rich
1-7: 4% / year => 75% survive, not a huge change over the Ordinary, but it is something.
8-20: 1% / year => 66% survive, so in the end, 10% change over the Ordinary. Hmm. Might do something a bit more dramatic.

Lets try 30% drop?
Rich (30% drop in lethality)
1-7: 3.5% / year => 78% survive, about 10% more than Ordinary
8-20: 0.875% / year => 70% survive or 15% more than Ordinary. Most importantly, it cuts the death toll by 25%.

Superlative (lets beef it to 50% drop in lethality)
1-7: 2.75% / year => 84% survive (still, 1 in 6 die so infant mortality is definitely there)
8-20: 0.625% / year => 77% survive, or cutting the death toll by half. Sounds about right. In other words, 1 in 4 children might die but the others survive.

Given that Rich and Superlative families tend to produce more children as well, the PKs are almost guaranteed to have spares for the next generation... who need to be equipped or dowried...

Also, note that those numbers did not take into account the modifiers from wars or disease or famine. All of those will wreck havoc amongst the populace, pretty much plunging it back to the bad old days of 1/3 surviving. Of course, it would need to be a constant low level threat or a harder shock.

Hm, I miscalculated.

I wanted about 50% survival.
I suggest the best way to make it correct is to stop any survival rolls after age 8.

Hi Greg,
dont take the blame, it was I who did the math for BoE...
The 50% at 8yrs was build in fully intentionally, as I (mis)understood that was your desire.
The tables were build upon medieval life expectancies (according wikipedia)

The average life expectancy for a male child born in the UK between 1276 and 1300 was 31.3 years. In 1998, it is 76.

However, by the time the 13th-Century boy had reached 20 he could hope to live to 45, and if he made it to 30 he had a good chance of making it into his fifties.
Medieval Britain[17][18] 30 At age 21, life expectancy an additional 43 years (total age 64).[19]

Life expectancy increases with age as the individual survives the higher mortality rates associated with childhood. For instance, the table above listed life expectancy at birth in Medieval Britain at 30. A male member of the English aristocracy at the same period could expect to live, having survived until the age of 21[19]:

1200-1300 C.E.: 43 years (to age 64)
1300-1400 C.E.: 34 years (to age 55) (due to the impact of the Black Death)
1400-1500 C.E.: 48 years (to age 69)
1500-1550 C.E.: 50 years (to age 71).

The math in BoE was build to give:
50% mortality 1-7yr
30 yrs life expectancy at birth
+44yrs life expectancy at 21 (so to 65) [actually with BoE numbers more 58]

fg,
Thijs

http://www.sarahwoodbury.com/life-expectancy-in-the-middle-ages/
some say up to 1/3 of all died before the age of 5

fg,
Thijs

King Edward and his first wife, Isabella, produced 16 children. Of those, five were sons. Of those, only Edward, their last child, born in 1284, lived to adulthood and inherited the kingdom.
Of their 11 daughters, five lived to adulthood and six died before the age of three.
And these were Superlative rich... [though I think all that inbreeding/genetic diseases didnt help]

fg,
Thijs

http://www.sarahwoodbury.com/life-expectancy-in-the-middle-ages/
some say up to 1/3 of all died before the age of 5

fg,
Thijs


If you want 30% survival at 8, then mortality should be changed from 1-2 to 1..
I would simply give all Rich knights a +1 on this roll (and make all those poor ones suffer).

fg
Thijs

http://www.sarahwoodbury.com/life-expectancy-in-the-middle-ages/
some say up to 1/3 of all died before the age of 5


Those numbers surely include all the peasants and prostitutes and so forth.

As for King Edward & Isabella, outliers always exist. Unless you propose that we make 16 children / wife the new norm, too? :)

Nope, that's nobility only..

but:
http://books.google.nl/books?id=T4DLK7zLxYMC&lpg=PP1&pg=PA8&redir_esc=y#v =onepage&q&f=false

Good information book... (p376)
(p9)
again 10% mortality women mentioned here again [10% in total, not per pregnancy!]
20% kids didnt make first year (including 10% stillborn) I think we need to include these in the childbirth table
Then about 25% made it to 5.. And 70% kids made 16...
Seems we need to update the tables.. we only have 40% reaching 16

fg,
Thijs

Then about 25% made it to 5.. And 70% kids made 16...


Oh, you meant 30% -mortality- amongst the noble children. You wrote 30% surviving, which I thought was very low. 70% survival rate I can accept without problems. :)

At this moment it's 50% that live. If you want 70% to live, you need a +1..

fg,
Thijs

At this moment it's 50% that live. If you want 70% to live, you need a +1..


Yep. 0.95^7 = 69.8%.