IIRC that particular character played through (on top of many homebrewed adventures) T1, the Slaver series, S3, S4 and WG4, and the GDQ series, probably not in that specific order. The massive giants encounter routed us, but we (mostly) survived and came back for more with better planning, though I can't remember what we did exactly.
Ok, that gives me a frame of reference.
The gas trap was an example; mass save or die effects were pretty common in early D&D, even if not that particular version. See also: gaze attacks from petrifying monsters or death gaze creatures (bodaks, boalisks, catoblepas, etc), the rooms full of radiation that force a save or die from everyone in S3, things like gas spores or yellow mold, etc.
Leaving aside passive hazards like yellow mold, which we were rightly paranoid about and used all sorts of techniques to avoid exposure... these happened all the time in your games? Because I can give a rant about how badly designed Bodaks are as monsters.
I think you're presuming a lot about the kinds of challenges we faced.
Possibly. Mostly I'm really interested in the kinds of challenges you faced.
We would just add more pcs, including potentially multiple pcs per player if needed.
Leveled up henchmen and other NPC associates were a convenient source of PC's should you unfortunately lose a main, and were often converted to PC's once your main got to the point you had invested so much you were sacred to risk them. This gradually developed an aesthetic of a living world we didn't have at first, when if a character died well you just rolled up a replacement and introduced him the next session as "Bob, Jr." or "Bob's younger brother" or whatever.
I think the refutation is aimed at your perception of what was viable. Were I to accept the premise that your character has to hit some or all of your bullet points from earlier, I'd be with you, but that simply wasn't my experience. I found all kinds of characters with relatively low arrays of stats to be viable. In fact, my first couple of years, we played 3d6 in order with 2-for-1 swaps (or 3-for-1, for certain stats) as outlined in... Mentzer(?) Basic, I believe. Characters were still fun to play and the game was still awesome. To me, that says that those characters were viable.
I don't have a problem with the assertion that a character with high stats is better, on the whole, than one with low stats. But I don't always think that means that character is more fun. And to me, what makes a character viable is a combination of two things: 1. Is it fun to play? and 2. Is it fun to play alongside?
What I noticed was an experience of fun decay where if you had a good character or if another player had a good character, then playing a substandard character - one that would never be capable like your good character - was increasingly less satisfying. When we were kids and first starting out, playing anything seemed pretty cool. We didn't question the rules much. It was how it was. If you had a bad character, well that was just the luck. Maybe you'd get lucky next time. However waiting for next time tends to become a bit of a drag.
That's not true, though- or at least, it's only true for Strength. A 15 Con gave you +1 to your hit points; a 15 Dex gave you +1 AC. And you are noticeably better as a spellcaster with a 13 Int or Wis than a 9. Then there are things like carrying capacity, system shock, reaction adjustment... You got, maybe not bonuses, but a better chance of many things going your way long before you hit 16.
+1 hit points for a M-U is like a 40% boost in h.p. +2 hit points is an 80%. The difference between 2 hit points and 3 hit points at 1st level isn't much - you are still in that 1d4 can kill you range. But the difference between 25 and 35 hit points at 3rd level is enormous. There is a 'squish point' defined by the average damage you'd expect to take if attacked by a monster you were likely to encounter that M-U's had a hard time getting beyond, which is one of the many reasons in 1e AD&D M-U's were never as godly as they were in 3e (when they got the same CON bonuses as a fighter and so had proportionately closer hit points). It's a lot easier to get beyond that squish point with 35 hit points than it is with 25. If you could get past that 1 round squish point, then by a combination of your own and party actions you were hard as a M-U to kill. So +1 or +2 turns out to be a very big deal in the long run. If you didn't have it, you were always going to be squishy.
The same sort of thing turns out to be true about DEX, though counter-intuitively not as much for the M-U as for other classes. You can't think about AD&D play like 3e play. In 3e play monsters have explicit strength scores and large bonuses to hit which means most things you'll encounter have chances to hit which are at least in the middle of the fortune range. So in 3e, a +1 to hit might mean you take ~5% less damage - 1 chance in 20 fails to hit you now. It's not a big deal. But in AD&D play, most things you encounter do not have explicit bonuses to hit. So it's relatively easy to bump your AC up into a range where the only hits you suffer are on the high end of the fortune range. And on the high end of the fortune range, that one extra bonus to AC becomes enormous. Instead of taking like 5% less damage, you are taking 25% or 33% or 50% less damage. Once you had the treasure to 'suit up' in plate mail (or later full plate), any character that could now was forcing those high ends of the range. And then at that point every AC bonus was gold, and every DEX bonus made you that much more survivable.
The reason it didn't matter as much for the M-U is that AC 9 versus AC 10 isn't as big of a deal as AC -1 versus AC 0. Again, middle of the fortune range or less plays very differently than top of the fortune range.
The same sort of thing is true about those system shock survival checks. Yes, it does matter that they are getting slowly better well before the top of the table. But a 99% SSS check isn't 1% better than 98%, but twice as good as 98% (1 in 50 chance) and 15 times as good as 85% (roughly 1 in 6 chance).
Speaking of different play experiences, I found that not having a high stat in 3e was far harder to deal with than in earlier editions.
We've been using point buy. I've had a few people go with stat arrays like 18, 18, 8, 8, 8, 8 but its much more typical to take a lot of 14's and such because there is a lot more MAD.