I posted on this upthread (
#103).
Now the stat adjustment rules actually tend to make Moldvay Basic one of the better balanced versions of class D&D in my view - they tend to reduce the likelihood that a cleric with 13 STR will outshine a fighter with 12 STR, for example.
Eh. I don't think a 13 STR Cleric is outshining the Fighter anyways. The Fighter still is a fighter, with all the benefits of using magical swords, spears and better attacks (at higher levels). Secondly, why are we comparing a 13 STR Cleric with a 12 STR Fighter?
Either the player has rolled 13 or they've rolled 12. They can play a Fighter with +1 attack and 5% experience bonus, or they can play a Cleric with +1 attack. The Fighter makes better use of the higher STR.
But in 1st level play, good die rollls let you play an Elf rather than a MU, which is a strict power-up.
Also not true. Elves have a much higher XP cost than MUs. Not to mention a harder chance of +10% bonus XP. Which means, an 18 Int MU is going to level up far quicker than the elf.
We have an elf in our current campaign, and he has by-far the most XP (out of 20+ characters) because that character has survived since the beginning of the campaign. Yet, everyone else is right there with them in terms of level. If someone else had the same XP, they'd be a level or two ahead. The downside of an elf is that you are going to level much slower.
And Dwarves are close to a srict power up from fighters, too. (The effective +2 to save seems a more-than-fair trade off for not being able to use a two-handed sword.)
This might be a better argument. But, again. Dwarves need more XP to level. So, sure. If you're willing to pay more XP for the +2.
And thieves' skill chances are so low for everything except climbing (and, maybe, listening) that those abilities make a doubtful practical contribution - particularly in a game where the generic penalty for failure is PC death. (I think Moldvay D&D could be improved by replacing the current rules for thief failure with some sort of "complication" rule - so thieves' schtick would be to both introduce and deal with complications, rather than just die Black Dougal-style.)
It just depends. Thieves are definitely the worst class in terms of their comparison to HP, AC, weapons use and so on. And, we have house-ruled it so that you get +Dex mod to your skills, which improves the odds a bit. But, thieves shine at 4th level+ - and they have the lowest XP to get there. I can have a 3rd Level thief while your elf is still 1st level.
I've also witnessed a 4th level thief have an invisibility spell cast on them, and use their skills to climb into a tower and backstab the BBEG in a pretty amazing display of stealth and assassination.
I also don't get the "generic penalty for failure is death". Maybe elaborate? I can't imagine a generic penalty for failure. It all just depends on the fiction and what's happening in the game. Certainly, falling might hurt - but as you noted, a Thief has a very small chance of failing at climbing, even at 1st level.
This isn't intended as a criticsm of Moldvay Basic, by the way. I think it can be fun despite being unbalanced (and have had fun with it). But as I said in my earlier post, I can also see why the Tunnels & Trolls designers decided to be more upfront about the lottery aspects of the game.
And, I disagree with your "lottery theory".
Surviving in B/X has less to do with your character's abilities and more to do with with player skill and knowledge.
We've had people roll up characters with 18 or 17 in multiple stats and die the first session, while characters much far more average stats, 10s and 12s, live to become 5th level (that's our highest level so far).
You know who survived? The player with experience with OS D&D. Players from 3E and 4E generally go through 2-3 characters before they start "getting it". And, the two players I'm thinking of, now both have 4th level characters after they went through a couple (remember, our elf has been adventuring since Day 1 and he's only 5th level).
But, once they get it, survival rate goes up dramatically. That's not a lottery. That's skill.