Balancing All ThisIf I am a game designer, I want that green area to be as tight as possible (while still feeling good). You don't want too much difference between an average character and an optimized one, because you don't want min-max'ed "best" character designs blowing out average encounters. You want them doing well and feeling good about their choices, but you don't want them pushing everything over with ease.
Less than optimized characters? I don't really care about them and they can fall off the balance curve if they are terribly designed. You want some of this "lots of terrible designs" thing going on so you can create that 'system mastery' feeling in your game where you try repeated designs and discover what works best and what gets you towards that red line of average expected competence and character power. I remember somewhere where the designers of D&D 3.0 said they included less-than optimal choices in character design just to fill out a range of good choices and bad choices, just like deck building in Magic the Gathering. The silly non-historical double-ended greatswords and warhammers come to mind...
Now, if every character design choice is equal? You are back to the B/X chart and none of this matters. I am sort of reminded of D&D 5's system, where if you want to be a certain type of fighter you pick the ability you are expected to take, such as the Fighting Styles and Class Archetypes in that system. The entire character design system in D&D 5 is a lot tighter than games like Pathfinder, with less choices but more focused in both balance and the abilities you are expected to take given how you want your character to perform. The envelope is tighter in D&D 5, but there are still bad choices given what you want to do (taking an archery fighting style as a fighter and never using a bow, for example).
Why This MattersAs a player? I want to design and min-max, and that is a big part of the fun for me. I also want the game to be balanced and have the fights not be too easy or too hard.
As a referee? I want to be able to predict player power to balance encounters and not have the game either be too easy or result in a total party wipe. I also do not want "design as distraction" where players experience choice paralysis or the entire design system takes over the game.
Both players and referees want balance and to avoid the extremes of too easy or too hard. I like the encounter balancing systems of the newer rules, but for me as a referee, I never really had a problem balancing a B/X experience either - although I know that opinion is outside the current view of things.
To me, in a B/X experience, balance was more of a player-focused concern - they knew what they could fight (based on experience), and they were the ones who had to judge if they should open that next door. My secret "good DM" promise to players was not to put any monsters on the current level that would wipe them all out in the blink of an eye (something again, I learned through experience and the simple and mostly predictable nature of B/X combats plus limited monster lists). No ancient red dragons above dungeon level 7, please. Keep hit dice equal to dungeon level and player level, and use quantity and encounter composition to match party strength. Got it.
If I screwed up encounter balance and things started to go very badly? GM fiat time. Make some monsters weaker, have some run away, give the players an out, or make the monsters hold back a little out of caution. Fudging rolls was usually a last resort for me, and if I did, it was usually on monster to-hits while the players made a hasty retreat to lick their wounds and regroup.
Player Skill versus Design SkillThere are times when I want to take character design skill out of a game and just have a system that rewards creative play and player ingenuity. If your level 5 fighter is just like every other, then how you play them will make a big difference in your success or failure. Of course, there is the factor of random chance, but part of playing an old-school B/X game also involves a bit of risk mitigation and understanding random chances and trying to control odds.
I have had games where the character designs felt like they took over the game, and the players were focused on getting a numerical advantage through character design. I have seen games where a character's design and numerical advantage acted as a disincentive to attempting actions outside of their area of expertise. It is like am archery-focused fighter way above the range-combat power curve hesitating to get into melee combat because their character is only average at melee fighting.
A good referee will force characters outside of their comfort zones, but I found game systems with heavily min-max'ed character design systems make doing that a lot harder. I have had players disengage rather than be forced to fight outside of their numerical comfort zones. I don't blame the players though, I blame the game for putting them in that mindset. Some games tend to punish you hard for that risk-taking and out-of-the-box play, such as D&D 4 and the amount of optimizing needed to keep up with the content's ever-increasing challenge level (at least when we played, it changed several times as new monster manuals and revisions came out).
System Forgiveness and FlexibilityD&D 5 for us tends to be a very forgiving system. There is a lot of healing, character death is more difficult, there are many options and infinite-use spells for casters, and the game feels more like D&D 4's sort of MMO-inspired experience that is more player-friendly and focused. Characters are also mechanically complex with a lot of design options given the type of character you want to play. The game is also more story-focused like a modern narrative game, and as a result tends to reward "story based play" rather than the old-school "slay and loot" style.
B/X systems, for us, are a lot simpler, the characters are fast to design and die often, and the entire system is a lot less forgiving of bad luck or mistakes. They can approach the difficulty level of today's "rage games" in some insta-death adventures, and I find my players are a lot more crafty when they have less options and character advantages to fall back on. With less mechanical abilities, my great players are always trying to come up with creative ways to manipulate the situation to their advantage despite not having the "rules tools" to do so.
I have also seen less experienced players in old-school games "freeze up" because they don't think they can do much outside of "cast the spell" or "roll an attack." This is one of the hardest skills to pick up in systems that ;eave a lot up to interpretation, knowing that you as a player are free to come up with anything you can imagine you could do, and also that you are the referee should encourage and support those crazy plans and actions through fair judgments using the dice and/or ability scores to determine the chances to succeed or fail.
D&D 5 moved back from the "cover everything" sort of rules design where there are detailed rules for every action and leaves a lot up to players and referees. B/X systems are already there and I feel as a whole that moving back to more interpretive systems where less is more is a good thing. I don't need rules for everything, just guidelines on general things and me and my group can take it from there.
My Current Feelings
My Ideal Dungeon Game
It is that simple yet focused feeling, almost like a dungeon-game version of solitaire. I can't wait for my fighter to get to level two, get a slightly better to-hit, some treasure in his backpack, and maybe he now has 13 hp now. With every level he can go deeper and deeper, and my character really doesn't get all that more complex as he levels up. When he is hurt, he drinks a healing potion (if he has one), or heads back to town. The dungeon may restock when he comes back, and random encounters are always present in the halls, so getting back to where he was will be tricky.
With simple characters I could run a whole 4 character party myself one one sheet of paper for record-keeping - no computer programs needed to design characters and level them up. My fighter has chainmail and a sword, my rogue a dagger and leather armor, my mage a magic missile spell and a staff, my cleric chainmail, a shield, a mace, and cure light wounds. Some ability scores and hit points, some saves and to-hit numbers - and we are done. I don't have to reference the class areas of a player's handbook to know what special powers and feats each one can use - it is all here on the sheet.
This is B/X - I know this.