My House Rules
The default rule system for the game is Swords & Wizardry WhiteBox, a “retroclone” that emulates the original 1974 version of Dungeons & Dragons, but is much easier to read (Gary Gygax was a great game designer; a writer… not so much).
Rules as Written
The “Chance in Six” System
There is no Skill system in Old School D&D, and the intention is to resolve most actions purely through description and role-playing.
However, if we need to make a roll to resolve an action that isn’t an attack roll, saving throw, or a cleric’s Turn Undead ability, we use the “chance in 6”, meaning we roll a d6 and try to roll that number or lower. For example, a 2 in 6 chance means a roll of 1 or 2 on a d6 is a success.
The "baseline" chance in six is 2, based on the roll required to open a stuck door. This can be modified by a relevant ability score (such as Strength). Certain races, like Elves and Dwarves, have increased chances to do certain things. For example, Elves have twice the normal chances to hear noise when listening at a door. Finally, Thieves have a "Thievery" ability, which eventually gives them a 5 in 6 chance to do things like pick a lock or sneak up on a foe (though it begins with a lowly 1 in 6 chance).
The specified Chance in Six rolls in the Original Rules are:
2 in 6 chance to open a stuck door. I will let you roll this, because you would know whether you opened the door or not. Only one attempt per door, per trip to the dungeon, but up to three PCs can attempt, all pushing at the same time. If they succeed this way, they fall into the room and onto the floor, and whatever is in the room gets a Surprise round (one free action). The same check can be used for other feats of Strength, such as lifting the bars of a portcullis.
1 in 6 chance to hear noise when listening at a door. I will roll this secretly, because you wouldn't know whether you failed to hear something or there was simply nothing to hear. Again, up to three PCs can listen at the door at once. There are no adverse consequences. Elves have a 2 in 6 chance to hear noise. Undead don't make any noise.
2 in 6 chance to find a Secret or Hidden Door if you are searching the correct 10 foot section of wall. A successful roll does not necessarily tell you how to open the door. Elves have a 4 in 6 chance, and a 2 in 6 chance to notice secret doors when merely passing by. I will roll these checks in secret, because you wouldn't know whether you failed to find the door or there simply is no door to find.
When the party first encounters a monster or group of monsters, they usually have a 2 in 6 chance of "surprising" the monsters, meaning they get a free round in which to act (which they can use to attack, cast a spell, run away, start talking, or whatever they want to do). Monsters generally have the same chance to surprise the party (giving them the free action), and many monsters have a better than 2 in 6 chance (bugbears surprise on a 3 or lower). It is possible for both parties to be surprised, cancelling each other out.
When you do something that potentially triggers a trap, there is only a 2 in 6 chance the trap actually goes off. I roll for each PC who could trigger the trap, so if it's a hidden pit trap in the floor, there's a good chance at least one of you is falling in. So keep your eyes peeled and bring a ten-foot pole. Dwarves have a 2 in 6 chance to notice something "off" about the stonework, and a 4 in 6 chance when actively looking in the right spot. Most traps should be discoverable through the area description. The purpose of a trap is to test your creativity in avoiding the trap, not to trick you into dying.
And that's pretty much it.
I also have a number of house rules, listed below. Some are up for discussion.
These are House Rules I will be using in any case
Roll 3d6 in order. The order should be Strength, Intelligence, Wisdom, Constitution, Dexterity, Charisma (the original order), but I will also accept Strength, Intelligence, Wisdom, Dexterity, Constitution, Charisma (the Greyhawk order).
I prefer you roll up your character at the table, but it is not a bad idea to have a few back-up characters as well (I have some pre-rolled characters in case of untimely death).
To give you an example of how "old school" stats look, here is Xylarthen the Magic-User, the character example used in the original game:
- Name: Xylarthen Class: Magic-User
- Strength: 6 Intelligence: 11 Wisdom: 13
- Constitution: 12 Dexterity: 9 Charisma: 8
- Name: Xylarthen Class: Magic-User
Gygax writes: "This supposed player would have progressed faster as a Cleric, but because of a personal preference for magic opted for that class. With a strength of only 6 there was no real chance for him to become a fighter. His constitutional score indicates good health and the ability to take punishment of most forms. A dexterity of 9 (low average) means that he will not be particularly fast nor accurate. He is below average in charisma, but not hopelessly so."
You can “buff” your main attribute by one point for every 2 points you lower another attribute. However, you may not lower any attribute below 9, and you may not lower Constitution or Charisma at all. (EG a Fighter with 14 Strength and 11 Intelligence can raise their Strength to 15 - getting that +1 bonus - by lowering their Intelligence to 9).
Dwarves have a 2 in 6 chance of noticing sloping stone passages, as well as traps, secret doors, and other relevant hidden features specifically related to stonework, even if they are not actively searching. The DM will make this roll in secret. Dwarves have a 4 in 6 chance to notice the above if they are actively searching in the correct place (again, roll in secret).
Dwarves get a +2 bonus to AC when fighting giants, but no bonus when fighting human-sized creatures (they’re small, but not that small). Dwarves take full damage from large opponents, however.
Elves have a 2 in 6 chance of noticing secret or otherwise hidden doors even when not actively searching. The DM will make this roll in secret. Elves have a 4 in 6 chance of finding secret or hidden doors when actively searching in the correct place (again, roll in secret).
Elves can choose to operate in only one class at the time of character creation. When acting as a Fighter, Elves may not cast spells. When acting as a Magic-User, Elves may not wear armour unless they own Elven Chainmail. Elves do not “automatically” get Elven Chainmail. They have to find it in a dungeon like everyone else.
Elves whose Dexterity is higher than both their Strength and Intelligence may opt for the Thief class. Elf thieves may advance to any level.
We will not be using the “Elf Variant” or “Elf as Class” rule (which comes from the Basic, rather than Original).
A halfling whose Dexterity is higher than their Strength may opt for the Thief class. Halfling thieves may advance to any level. Halflings have a 4 in 6 chance to hide (given a reasonable opportunity) when not in combat. This can be modified by their Dexterity bonus to a maximum 5 in 6 chance. The DM will roll this in secret, because you always think you’re hidden.
Out of combat and exploration, time is not carefully tracked. When exploring a dungeon or interior area, we track time in “turns” which are 10 minutes of game time. During combat we track time in “rounds” of 1 minute. Otherwise, time is loose and free-form.
You may move your movement rate times 10 in feet in 1 turn and perform another action, or move twice. (E.G. if your movement is 12, you can move 120 feet and perform an action, or move 240 feet).
You may move your rate times 2 in miles in one day of overland travel. (E.G. if your movement is 12, you may walk 24 miles per day over open ground.)
During combat, you may move up to your movement rate divided by 3, times 10 per round. (E.G. if your movement rate is 12, you may move up to 40 feet per round - 12/3 = 4; 4x10 = 40.)
Initiative and Order of Combat
This will be discussed in Combat.
After each combat, a PC can “bind the wounds” of one other PC, restoring 1d4 hit points. This takes ten minutes of game time and provokes a Wandering Monster check (meaning the DM will roll in secret to see if a Wandering Monster interrupts you).
You will notice that spells only go up to level 6 (or 5 for clerics), and that some iconic spells like Magic Missile don’t exist. This is the original list of spells in 1974. I will, however, put the complete list of spells in the game, in scrolls and spellbooks. But you will have to find these spells in dungeons and other dangerous places, or defeat powerful magic-users, to get access to them. You can also create your own spells.
Casting from scrolls
If you cast a spell by reading it from a scroll, it is cast as if you were a 6th level spellcaster (or the minimum level required to cast the spell), and you may cast it regardless of the spell’s actual level. However, the spell disappears from the scroll once read out (even if the spell fails) and cannot be “learned” or copied into a spellbook. If a Magic-User copies a spell from a scroll into their spellbook or a Cleric attempts to “learn” a spell from a scroll, the spell is copied/learned at its actual level.
This means that there may be a tactical advantage to casting from a scroll, as such a spell would be more powerful or more likely to succeed. However, you can only use it once.
Ability score bonuses
Fighters may use their Strength bonus for attack rolls and damage rolls. Magic-users may use their Intelligence bonus to gain an extra spell at first level. Clerics may use their Wisdom bonus to gain a spell at first level.
We are using the Old School Descending Armour Class. Without any armour, your AC is 9. Adding armour and shields lowers your AC. Lower AC is better; higher AC is worse.
You still need to roll high on a d20 to hit.
Every PC has a number they need to roll To Hit Armour Class 0 (THAC0). For most level 1 PCs, that number is 19. To see what AC you hit, roll a d20 and subtract your roll from your THAC0. The result is the AC you hit.
Example: Your THAC0 is 19. You roll a d20 and get 12. 19 - 12 = 7, so you hit up to AC 7. If the target's AC was 7 or higher (worse), the DM will declare a hit, and you can roll damage. If the target has an AC of 6 or lower (better), you miss.
Fighters may fight with a one-handed weapon in each hand, giving them an additional +1 to attack rolls, but not damage rolls (they may still get a +1 to damage from their Strength bonus). They do not get an additional attack.
Suggested House Rules
These are House Rules I would like to use, but can be talked out of.
Fighters of level 2 or higher may get an additional attack against weak foes. The number of attacks equals the Fighter’s level divided by the hit dice of the target. A fighter is always entitled to at least one attack. If this rule is used, monsters will get multiple attacks using the same formula (meaning a troll would get 6 attacks against a first-level PC).
Elf class advancement
Elves may switch between the Fighter and Magic-User class, but must return to their home base to make this switch. (E.G. an elf acting as a magic-user must return to their home base and pick up their armour and weapons if they want to switch to Fighter. They must leave their spellbook behind and forgo using spells until they switch back). Elves level up in each class as soon as they have enough XP. For example, an elf with 2,000 XP is a level 2 Fighter but still a level 1 Magic-User (until they reach 2,500 XP).
Critical hits and fails
The Original game did not have a rule about “natural 20s” and “natural 1s”, and we don’t really need them.
However, I would suggest that Fighters and monsters can shatter or ruin one piece of armour on a natural 20.
Shields will go first, if any. Then armour will be downgraded by 2 for each critical hit. Thus a fighter with shield and plate (AC 17) would have to sustain four critical hits before their AC goes down to 10. However, leather armour is ruined after only one crit.
If you survive the encounter, you must buy new armour or have it repair (if possible).
This rule does not apply to magic armour or AC that is the result of magic (like incorporeal undead).
By contrast, if a PC rolls a natural 1 on their attack, their weapon is shattered and ruined. A monster should sustain a similar disadvantage on a natural 1, if this rule is used.
Clerics can bind the wounds of 2 PCs, rather than one. This compensates for the fact that level 1 Clerics generally don’t get any spells.
The Greyhawk supplement introduced a system where Magic-Users had to roll percentile dice to see if they knew a given spell. I like this rule, because it adds an element of randomness to the game, and can inspire players to consider spells that seem “suboptimal”. So I would suggest that Magic-user has a (6-[spell-level]) chance in 6 to "know" a new spell (find it in their spellbook). This does not apply to finding spells in scrolls and other spellbooks.
Proposed House Rules
These are House Rules drawn from other retroclones. They do not reflect the 1974 game, but they can make game play smoother and faster. If the intention is to stick to “authentic” 1974 D&D, we may not want to use these.
Shatter the Shield
Fighters who have shields can choose to “shatter” their shield instead of taking damage. You can choose to shatter the shield after the DM declares the damage. You then take no damage on that attack, but you lose you shield bonus to AC until you buy a new shield.
To simplify encumbrance, a character may carry as many items as their Strength score. 10 coins count as 1 item.
If you carry more items than your Strength score, you have disadvantage on all d20 rolls and a -1 penalty to any physical chance in 6 roll, but worn items (armour, shields, weapons) do not count as carried. You cannot carry more than twice your Strength score.
This rule comes from The Black Hack, and may actually limit how much loot you can carry, plus it gives more benefit to characters with a high strength score than the Original game did.
Instead of the movement rule above, we can use four abstract measurements of movement and distance: Close, Nearby, Far Away, and Distant.
Close means in melee range (10 feet or less) .
Nearby is close enough that you can move into melee range and attack in the same round (more than 10 feet but less than your full movement) .
Far Away means you can move into melee range in one round, but you cannot attack until the next round.
Distant means you need 2 rounds of movement to get into melee range, and can attack on the third round.
NOTE: if you move into melee range, but cannot attack until the next round, the monster can attack you on its turn!
If we use this rule, then “encumbered” PCs can only ever move to the Nearby range on their turn. This rule also comes from The Black Hack, and would make travel and dungeon exploration far less precise than the Original game did.
There are no negative hit points in the Original game. However, when you drop to 0 hp, instead of just dying, you can be taken Out of Action (OofA). This means you are unconscious and unable to act. Then, if the rest of the party survives or can drag your body out of danger, you can roll on the table below to find out what happens to you:
1 KO’d. Once out of danger, you wake up with 1d4 hit points.
2 Concussed. As above, plus Disadvantage for the next hour.
3 Cracked bones. As 1, plus -2 to Strength, Dex, and Con for 24 hours.
4 Crippled. As 1, plus Strength or Dex is -2 permanently.
5 Disfigured. As 1, plus Charisma is -4 permanently.
This comes from The Black Hack and makes the game less lethal while still providing a consequence for losing a fight.
Instead of tracking consumable items like arrows, rations, and torches, we can assign these things a Usage Die.
The second time you use something (and each subsequent time) you roll the usage die (e.g. a d10 for arrows). If it comes up 1 or 2, you downgrade it to the next lowest die (e.g. a d8). If you roll 1 or 2 on a d4, you're out of that item.
Buying more of it restores your usage die to it's maximum.
This rule comes from the Black Hack and preserves the "resource draining" and "push your luck" aspects of the game, without reducing it to an accountancy exercise.
Usage dice for rest
The Original Game requires you to take one ten minute turn of rest for every five turns of exploration or suffer a penalty on all dice rolls.
Instead of that, we could say you have a d10 of "stamina". From your second turn on, we roll the usage die. When it reaches 1 or 2 on a d4, you must rest for ten minutes (restoring the die to a d10).