I don't know how Wizards and Warriors handles HP/SP growth, but it is possible it may take an approach similar to the one used in classic Wizardry (1-3 and 5). When you level up, the game rolls all of your hit dice (not just the newest one); if the result is greater than your max HP, you will get the full amount, but if not, you only get 1 HP.

This means that (at least in classic Wizardry):
* If you get a good HP roll one level, you will get only 1 HP for the next several levels.
* One good HP roll can wipe out many levels of bad HP rolls.
* Gaining Vitality will often result in a significant HP boost either on the current level or the next level (I don't remember if different Wizardry versions handled this differently). Conversely, a loss of Vitality can result in you only gaining 1 HP per level until you get it back.
* If you change class, or hack your HP to a high number, expect to gain only 1 HP per level up for a while, until your level catches up to your HP.
* If you hack your level to a high level, ans also hack your XP high enough to gain another level, that level will give you a lot of HP. If you hack your HP to a low number (like 1) before leveling up you will, again, get a large amount of HP.
* If you keep reloading until you get good HP gains, eventually it will be less and less likely that you'll roll high enough to get more than 1 HP. (This is the effect you're observing, and is why I suspect HP gains might work something like this.)

In other words, unless your HP is low enough to be an issue, don't worry about bad HP rolls; your HP will balance itself on its own, and using save/reload to get more HP won't help that much, and will end up being frustrating when you keep seeing 1 HP gains.

Your hit points are rolled based on class and level. If the new roll is less or equal to your current HP, you get 1 HP. Eventually, when the rolls are low enough for long enough, you will get a huge amount of HP all at once. It always evens out eventually, reloading just isn't worth the time. After a while you will seem to *always* get 1 HP until you're in a severe deficit of HP for your class/level. Then, boom, tens of HP all at once. Also, may want to read some spell books if SP are an issue.

People used to save Barbarian to level last and highest for this reason. Switching from Barbarian too early locks off the highest HP/level combination until the adventure is reset.

One old Ironworks thread on the matter:
http://www.ironworksforum.com/forum/showthread.php?t=32473&highlight=points

Thanks for the explanation. By SP I meant skill points, not spell points. I suppose in the 20 years since this game came out, I've gotten used to (better) systems with less RNG for stats/skills/hp, etc.

Looks like I'm in the "Left Barbarian Too Soon Club", but fortunately the two characters in question are already at 100+.

Funny thing is, at least when it comes to HP, this is actually less random than the system used in classic (Advanced) Dungeons and Dragons. In D&D, if you get a bunch of bad rolls early, you are stuck with them for the rest of your character's lifetime (excluding however the DM decides to handle level draining), while in classic Wizardry (and, if Lysanfae's post is accurate, Wizards and Warriors PC), a single good roll can wipe out a series of bad rolls. Do you happen to have any information on the HP/level for each class? (Also, do XP requirements at high levels vary by class, and if so, do you have any information on that?)