Good summary, Celebrim; and though I don't agree with all of your ideas I think we have much in common, starting with...
I believe 1e is still a system worth playing today. There are still things it does better than modern systems.
...this. I'm still playing it.
Flip AC around, as per 3e.
Critical hits, as per 3e, replacing the more swingy critical hit table generally used in 1e.
New fumble system hybridized with 3e.
I'm so used to the lower-is-better AC I'd never want to flip it. But I do allow AC to go below -10 if someone manages to get there, and above 10 should someone be so pathetic. Crits and fumbles are almost something each DM should probably tailor to their specific game and player tastes, with a basic idea for such suggested in the DMG as a default.
Drop most of Unearthed Arcana with its strictly superior martial classes, broken spells, no brainer weapon specialization, and so forth. In retrospect, most of UA is badly thought out. A revised UA is possible to retain the flavor of classes like the Cavelier and Barbarian.
Agreed, except Barbarian should not be a class at all - rather, it should be a sub*race* of Human. Bits of UA are worth saving; you just have to carefully sort through the chaff. I'd also suggest ignoring Oriental Adventures unless you're going for an Eastern-theme campaign.
Grant Humans some small bonus as 3e did (extra proficiencies perhaps, maybe 5% bonus to earned XP). Greatly open up level caps on demihumans (in many cases doubling them).
Making Humans playable can be rather easily done via setting. Non-Humans are shunned, cannot find training, are thrown out of most settlements on sight, etc., etc. Make this clear going in, and let the players decide what to play.
Disagree. I likes my Assassins!
Unified initiative system as 3e. Was about half-way here in late 1e anyway.
Unified and simpler init. system - convert everything to a 6-segment round, then roll d6 each round for initiative. Simultaneous actions all resolve at once (thus, two melee combatants on tied initiative *can* kill each other simultaneously, something that cannot possibly happen in 3-4e). In cases wehre something gets multiple attacks e.g. a claw-claw-bite or a high-level Fighter, each gets its own init. each round.
Remove exceptional strength table and normalize strength in a more unified approach. Fighters (and only fighters) now gain bonus strength as a function of level. Thieves now gain bonus dexterity as a function of level. (Multiclassed fighters or theives gain either half as fast.)
Not sure about this. Ex. Str. is an attempt to recognize that while strength *can* go off the charts, the 3-18 range is paramount. 3e solves this by letting stats go crazy, such that 3-18 becomes mostly irrelevant. But there has to be a way to allow for the Hercules' and Conans of the world, while retaining the idea that 18 Str. is the best a normal Human can hope for...and while not throwing out the 3-18 system.
What we've done is take the 18.01-18.00 range and break it out into integer numbers (thus, 18.41 = 19, up to 18.00 = 24) with Hill Giants checking in at 25 and Storm Giants capping it out at 30. We kind of had to do this becuase we took the percentile stat increments introduced with Cavaliers and gave them to all classes (which is a change I'd make again in a heartbeat), and it just doesn't work when Str. is already on its own percentile.
All classes gain multiple attacks per round at higher levels, corresponding to the point where there THAC0 reached that of a corresponding fighter.
Thieves now use same attack progression tables as clerics. Wizards now use same attack progression as theives. This is actually 3e in disguise.
Clerics can spontaneously cast cure spells as 3e. Clerical orisons become standard in a manner similar to 3e.
Close to what we've done. Clerics are completely "wild card" in what spells they can cast; I've recently done the same with wizard-types and so far I'm pleased with the result. I'm just too lazy to design different spell lists for each deity, which would be the ideal solution.
I've messed with the attack matrix and smoothed it out for all classes. The original has odd jumps and gaps for all classes. Wizards still suck at it, though, and Thieves aren't much better.
Monsters gain explicit attributes as 3e. Many monsters already have implicit attributes (range of intelligence scores, bonuses to hit and damage, etc.) this would just make it implicit. I was beginning to do this in late 1e anyway.
Monsters have explicit attributes, I just don't care what they are until it becomes relevant e.g. when I need to know how dumb this Orc you just charmed is, I roll d% behind the screen and let that be a guide. But strong monsters get their to-hit and damage bonuses, and dextrous ones get the AC/missile bonuses if not already listed.
Bonus spells/level for M-Us as 3e. Increased access to spells at low levels as 3e. 3e cantrips and system replace 1e cantrips system.
Max hitpoints at 1st level as per 3e. I knew some DMs doing this already back in the day.
We introduced Body Points, that all beings have. Normal rolled hit points become Fatigue Points. The mechanics work similar to Wound-Vitality points in the Star Wars game. End result: 1st-level characters have a few more h.p.
Drop illusionists as a subclass, and use specialist M-Us like 2e.
Keep Illusionists, and add Necromancers. All the others are too similar to bother breaking out.
Replace 'backstab' with system similar to 'sneak attack'.
One of the best things about backstab was that it took effort to set up. 3e's sneak attack is far too easy for the Thief.
Balance the XP earned system to better reflect challenge. Balance the XP required to level to better reflect actual power of class. Several Dragon magazine articles provide a very good start to this.
And drop ExP for treasure, replacing it if desired with story awards or mission bonuses. In any case, slow the advancement.
Create unified base 'Perception' and 'Alertness' subsystems to replace the myriad of subsystems for finding secret doors and determining surpise. This could be as simple as turning them in to percentage scores and turning all modifiers into percentages (similar to 'bend bars' checks.). Modifiers to find secret doors or avoiding/achieving suprise become bonuses/penalities to this subsystem. Wisdom and dexterity provide/modifiy base success chances.
Interesting. I usually use a d20-roll-low for perception, winging the difficulty every time. Secret doors and trap finding I usually use the Thief tables. Surprise is and always will be on a d6; "six-sided!" being one of the game's canonical sayings when trouble is afoot.
Drop multiple missile attacks per segment on suprise.
Drop attacks = level if HD less than 1.
Drop weapon speed factors.
Done.
Explicitly define the difference between armor class and a bonus to armor class so as to clarify how the weapon vs. AC modifiers work.
Add lines for claw, talon, bite, fang/tusk/horn to weapon vs. AC modifiers. Needed 'to hit' vs. AC 0-10 (remember, we reversed) becomes standard line in monster entires along side attribute scores. This slightly increases size of entries (from 2 lines to 4) but speeds play.
Easier to just get rid of weapon vs. AC modifiers. Life's too short.
Poison/diseave damage generally as per 3e, except as per 'venom' type systems where damage reoccures until saves are made.
Or just be more creative on what poisons etc. can do to you. Strongly suggest *not* venturing into ability damage like 3e does, it's a pain in 1e where *any* stat going to 0 means you're dead, and there's no mechanism at all for recovery of lost stats.
Port in most of the AoO from 3e (with the exception of most movment based AoO). I actually had got most of way here by late 1e.
We have a very simple AoO system and I'd not want to take it any further, having seen what happened with 3e. Messy!
Use the DR/regeneration/fast healing system from 3.0 to replace 1e's absolute immunities.
Or have both available. Use as desired.
Make psionic combat slower (same speed as normal combat) and somewhat more random (so that its not so predictable of a win for the side with the most points) and tied more explicitly to level/HD. Also, make it have a more 'rock/paper/scissors' aspect so that certain defenses successfully counter certain attacks but are vulnerable to others.
I ended up solving the psionic problem (after many failed attempts) by dropping psionics as a PC ability entirely. I kept them in the arsenals of a few iconic monsters (Mind Flayers, Demons, etc.) but that's it.
Lanefan