I would like to use this for Nathan because because I rolled 2 hit points for his 2nd level hp.  You can open Ultimate Campaign to page 188 to read about it.  In short:

* Retraining of any type costs 10 gp x [char lvl] x [days spent retraining]

* Retraining HP requires me to go to a martial academy or monk monastery, like Honor's Glen, and spend 3 days of consecutive retraining to gain 1 max HP.  (You cannot retrain your HP above max, obviously)

* I would like to go to Honor's Glen during downtime and gain, say, 3 hit points from training, which would cost 270 gp and 9 days of downtime at lvl 3. 

My first thought while reading this was that Retraining HP is too good b/c it makes the Toughness Feat obsolete.  If you roll average HP then you could spend on average, say, 400 gp per level over your first 5 levels to gain about 4 hit points/lvl.  So you're basically buying a slotless item that gives you 20 HP at lvl 5 for about 2000 gold.

My second thought was: that's not really overpowered after all.  Money has a lot of value elsewhere, especially at low levels, and people who happen to roll high are getting the same benefit for free.  My build includes the Toughness feat at lvl 7 anyway, which I might want to keep--even if retraining is allowed.

So I would like to do this during our downtime.  Any objections?

I don't have a huge objection, but it does totally nullify rolling for HP.  What we develop instead is a system where everyone rolls for how much their max HP will cost at level.  Gold may have other uses....but permanent HP is a really good thing to have (as we have discovered, lol).  My 2 cp says that this shoudl be available up to the level of an average roll.  This does not affect CON or TOUGHNESS or any other HP bonuses.  This only affects the variabel roll.

In otherwords:

HD              Max Trainable
d6                4
d8                5
d10             6
d12             7

So in Nathan's case, his 2 hp can become 5 hp, but no more (with feats and con not affected).

I like that plan.  I was going to do that anyway, for basically those reasons.

After thinking about this, I am opposed to Nathan going to Honor's Glen to train...

I think he should ask Adeon, Braun, etc. for matrial training for 3 days

I disagree, and think it should be RAW. personally, it is not worth it to me to retrain HP. Therefore, I wont be spending money on it. On that same note, there are people who are trying to squeese every point of health out of their characters, and if they want to spend money getting to max, I have no problem allowing it

Thanks Mike.  Right now the discussion is moot because I only want to train to 5 hp per d8 die--and nobody wants to retrain to full hp; we'd all rather save the money for other stuff.  I keep changing my mind on what I would say if If someone hypothetically wanted to train to full hp but, because I have no strong opinion, it may be better to just allow rules as written. 

I pointed out retraining hp to Joe D, Brian, and Nick during a lull in the action last time, and their reaction was one big "meh".  That's another reason why retraining to full hp might not be overpowered:  nobody wants to do it.

EDIT:

It would be thematically cool for Nathan to get his training from an other PC, but training is a full 8-hour activity that precludes other downtime actions that day, and it would be unfair to take downtime away from another player.  (Paladin may have been joking; my sarcasm detector doesn't function at work.)

Lol not only that, but sarcasm is hard to detect on a forum.

I believe Keyes has reconsidered his position. I believe he wants to shoot for full hp. I personally, see no reason to not allow it if he wants to sink the time/money.