House rules handout from my '85-89 D&D nostalgia game

I've edited it a bit from the original in the course of typing it up again, but this is the gist of how I ran the campaign.
This game uses the three little brown books, and specified bits of Greyhawk. Some of the monsters and spells from Greyhawk will be introduced as well. I'm leaving out Blackmoor and later additions.

Character classes

Fighter
Magic User
Cleric
Thief
period.
All humanoid races can be any class. No level caps. Human society is dominant over half the map, and race relations problems will make up for the tactical benefits of non-human races.

Alignments

Alignments are the old three value Law, Neutrality, Chaos system, interpreted this humanocentric way, since this is a campaign world with a shrinking human realm bordering on an growing magical one:
Law: Believes that humanity and human social order is basically a good thing. Neutrality: Neither for nor against the continued existence of humans. Chaos: Inimical to human life.

Experience Points

Experience points will be given out for monsters killed at a rate somewhat over original canon, and for treasure spent after the adventure on carousing/training/charitable donations/etc. Money saved for a rainy day, spent to gear up, hire muscle or fortify will not give experience points. Magic items will give some experience when used at first. There will be roleplaying, painful lesson, and quest rewards. I have some rules of thumb for calculating XP, but I'm not going to spell out formulas.

COMBAT

Damage

• unarmed humans 1D3
• most normal weapons 1D6
• heavy crossbows 2D6
• most monster attacks 1D6
• special monster attacks: as noted in book 2 or by DM fiat

Chance to Hit Modifiers

Melee Weapons

• +1 Two handed weapons
• -1 Small weapons (dagger and handaxe)
• -1 Using two weapons, primary hand
• -2 Using two weapons -secondary (usually left hand) attack
• -2 Unarmed attacks by men & similar
• -1 Improvised weapons

Missile Weapons

• 0 Short range
• -1 Medium range
• -2 Long range
• +1 Crossbows

Situational modifiers

Helmetless men: A.C. averaged with A.C.9, round down (stronger)

Attack Roll conventions

To begin with there will be no fumbles but a roll of 1 will always miss. A roll of 20 will always hit, the hit will be for double damage if the attacker could hit on a 19 or less. The 20 will also entitle the attacker to a reroll for a 19 or 20 for an instant kill.

Number of Attacks/Actions

Characters who attack on the men attacking table will get to attack once for each level group they have. A level group is the set of levels which all attack with the same To Hit number. Thus a fighter gets two attacks at level 4-6 and three at level 7-9, etc. Fighters and some monsters may strike great blows. If they do so, roll only once to hit and if successful, do the damage of the sum of their normal number of blows. Thus a superhero can strike three times for 1D6 or once for 3D6.
Actions such as drawing a weapon take up the time of one attack. Some actions, such as rummaging around in a backpack for a potion, will take longer.
Rate of fire with missiles depends on the weapon. Self bows can shoot once per action if the minimum strength requirement for the weapon is met. Otherwise, they take an extra action to load and draw, or are impossible to shoot. Crossbows take a number of actions to load based on their power.

Bow	Min. STR to shoot	Min STR to shoot each action
Shortbow	3	7
Composite Bow	7	12
Longbow	8	13

Crossbow	Actions to reload
Light crossbow	2
Heavy crossbow	4

Initiative

Each character rolls 1D6 and act in the order of high roller to low roller in each combat round. If desired, a group may choose to act together on the leader's roll, the choice being made before any dice are rolled. Dexterity, wound status and situation may modify the rolls. If acting as a group, the modifiers that apply to the most negatively modified character in the group are used.

Attribute effects on combat

Strength has the effects tabulated in Greyhawk.
Dexterity modifies a character's initiative, melee, and missile attacks, and defense as detailed in the table below:

Dexterity	Modifier
3	-2
4-6	-1
7-14	0
15-17	+1
18	+2

HIT POINTS, WOUNDS, AND HEALING

Hit Points

Dice as per original D&D, not Greyhawk 4-6-8. Characters have bonus hit points equal to one half of their CON, round up. Monsters are hjit dice listed +5 H.P, unless under one hit die, then bonus is 0-4 based on size. Hit dice will be rolled anew at each level, the new hit point score being used if it is higher than the old.

Wounds

There will be no hit location rules in effect but I don't want the okay until you are dead phenomenon so the table below will govern wound effects on the characters. Calculate the threshold values for the character at 1/4, 1/2, and 3/4 of the total hit points.

Fraction HP lost	Effect
1/4	Roll 1D20: If over CON+Level then character takes a -1 on all rolls, reduce movement rate by one class (3"). Else no effect.
1/2	Roll 1D20: If over CON+Level then character takes a -2 on all rolls, reduce movement rate to 1/2 normal. Roll again with a second failure resulting in incapacitation for 1D6 turns. If first roll is successful, inflict the penalty given above for 1/4 loss roll failure.
3/4	Roll 1D20: If over CON+Level then character takes a -4 on all rolls, reduce movement rate two classes (6"). Roll again vs 2D6 turn incapacitation, at end of which, roll again vs 1D6 day incapacitation. If first roll is successful, inflict the penalty given above for 1/2 loss roll failure, without the incapacitation roll.

For NPCs if CON is not rolled or specified, assume it is a 10.

For minor NPCs in large melees the effects are simplified:
1/4 Roll 1D6: run away on 1 or 2
1/2 Roll 1D6: Pass out 1D6 turns on 1-2, then -2 on all rolls. Run away on 3 or 4, -2 on all rolls. 5-6 -1 on all rolls.
3/4 Roll 1D6: Pass out 2D6 turns on 1-3, then -4 on all rolls. Run away on 4 or 5 at -6" speed, -2 on all rolls. 6 -2 Keep fighting at all rolls.

If runaway impossible, fight on on 1-3, surrender on 4-6.

Healing

Natural

1/4 hit points restored per week's rest if CON roll is successful on 1D20.
Skilled aid can add bonuses to the roll. Bad conditions will subtract from the roll.
Roll of 1: Special recovery, get 1/2 back.
Roll of 20: condition worsens, lose additional 1/4 hit points. If reduced below zero by this loss, save vs illness and death on this table:
Roll 1D20:
Under 1/2 CON - character falls only to one hit point, not killed, not crippled.
1/2 CON to CON - Reduced to one hit point, shock to system reduces CON by 1 permanently
CON +1 to CON + Level - Reduce to 1 HP, CON -2 permanently, DEX and STR -1 permanently
Over CON + Level - Death by illness and infection

Magical(Clerical)

I'm not running healing as a quick combat tactic in this one.
Healing magic puts the recipient into a trance in which they will heal at 1 pt/turn until the total effect of the spell has occurred. If the healing is by clerical spells, the cleric must closely attend the recipient, maintaining concentration throughout, or the spell stops healing.
Magical healing in one day totalling over the character's CON can overload the character's system. Save vs magic or lose one point of CON for each multiple of CON exceeded. This loss is permanent.

Magic

Magic spells will be learned and cast in the basic fashion with spells memorized and cast once, with some allowance for casting unmemorized spells and casting over your maximum number at increased risk for flexibility. A die roll will be required to cast a spell successfully.
Magic users must roll less than or equal to INT + level to cast spells successfully. Clerics roll vs WIS + level. If failed, the spell is not normally lost from memory and can be reattempted.
A roll of 1 is a critical success. The spell works and is still retained in memory. If unmemorized, no spell is wiped from memory to provide the "slot". If overcast, no damage is suffered.
A roll of 20 is a critical failure. The spell fails and is lost from memory. Unmemorized spells will wipe a same level spell from memory. Overcast spells will inflict double overcasting damage to the caster.
Unmemorized spells: You may attempt to cast a spell you know but have not memorized for the day. There is a -2 penalty per spell level to the roll. Spells to an equivalent number of spell levels will be wiped from memory by the successful cast or a critical failure. Normally this would be one spell of the same level, but multiple lower level spells or a spell of higher level may be burned off for the magical energy.
Overcasting: Spells can be cast beyond the stated limits in the rules. They are cast as a minus as unmemorized spells. The caster will take 1 hit point damage per level of spell if the attempt fails and 1D6 hits per level of spell if the cast works, due to the extreme strain upon the caster's body and psyche involved. First level clerics can cast first level spells only by overcasting.
Preparation: A spellcaster can improve chances of success by using ritual and preparing the spell before casting it. The bonus will be up to 1D6 rolled secretly by the DM. The spellcaster must remain concentrating on the preparation, gaining 1 point per full turn up to the secret limit (turns beyond are wasted), expending 1GP worth of magical supplies per turn per level of spell.
Duration: Spell durations, where imposed by Greyhawk, will apply.
Area effect damage will be a hybrid between doing full damage to everyone in the area and dividing up the damage among the targets. Damage spells such as fireballs and lightning bolts which do not specify that the damage is to be applied to each target will divide the damage among their victims rather than apply their whole damage to each. Dragon breath and other such large area weapons will be applied the same way. Add 2D6 per target in the area over one to the total damage before dividing damage among the targets. So a five die fireball on one ogre does him 5 dice, minus half if saved. A five dice fireball on a group of 6 orcs will roll 5 + 10 dice, but divide the rolled damage by 6 to apply to each orc. The orcs will save individually to reduce damage.