AD&D Rules Modifications

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AD&D is a great game, but sometimes modifications are required. What is on this page is really a collection of house rules and similar such stuff... feel free to peruse and direct any comments, suggestions and further Mods my way! Get me at Rain or anywhere else (home, Uni etc).


Extra Slots on the Same Weapon

It seemed to me that the rules for non-fighter character classes being unable to specialize were unfair. If a thief has been using only a knife the entire time they have been around, why should they then take a proficiency in short sword or bow when they've not been using one? So it seemed sensible to modify the system so that non-fighters could dedicate more slots to their weapons, but without negating the fighter's advantage of being able to specialize. So it is that I developed rules whereby it takes non-fighters five slots to do what fighters can do in two. This coupled with the fact that the other classes do not get as many weapon proficiencies as fighters means that it works quite well.
Rogues, clerics and mages (and any other character classes not capable of specialization) can put extra slots into any weapon they use regularly, to the following effect:
No. Slots Attacks/round To Hit Mod. Damage Mod.
1 1/1 0 0
2 3/2 0 0
3 3/2 +1 0
4 3/2 +1 +1
5 3/2 +2 +2

For bows or thrown weapons like daggers:

No. Slots Attacks/round To Hit Mod. Damage Mod. Other Mods.
1 2/1 0 0 n/a
2 2/1 +1 0 +2 to hit point blank, 1 shot before initiative.
3 2/1 +2 0 +2 to hit point blank, 1 shot before initiative.
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One subject AD&D most definitely does not cover is sex and pregnancy, probably because it is aimed at young people as well as the older ones. However, every now and again (and in some settings, all the damned time) the chance for a character or NPC to get pregnant comes up and as a DM it is your dutiful responsibility to roll the dice and hope for the worst.
To this extent, these rules are designed to give a gist for how likely a preganancy is, based on constitution and race. I made them up myself, but have seen many different systems out there, so if you don't like this one there's probably one to suit your needs (alternatively, you could just write one yourself).

Percentage chance of pregnancy = 2 x Female’s CON + male CON.
Eg: female with Con 12 and male with Con 10 have:
2 x (12) + 10 = 34% chance of pregnancy per ‘session’
. Due to the differences in longevity between the races, the following modifiers also apply:
Racial Modifiers:
Race of Female Race of Male Modifier
Human Human 0%
Human Elf -5%
Human Half-elf 0%
Human Dwarf -8%
Human Halfling -5%
Elf Human -15%
Elf Elf -20%
Elf Half-elf -15%
Elf Dwarf No conception
Elf Halfling -15%
Half-elf Human 0%
Half-elf Elf -5%
Half-elf Half-elf 0%
Half-elf Dwarf -30%
Half-elf Halfling -5%
Dwarf Human -15%
Dwarf Elf No conception
Dwarf Half-elf -30%
Dwarf Dwarf -20%
Dwarf Halfling -40%
Halfling Human -5%
Halfling Elf -10%
Halfling Half-elf -5%
Halfling Dwarf -40%
Halfling Halfling -10%
These modifiers are based upon the fact that all races have approximately the same number of children, but most live longer, therefore they must be less fertile than humans. Also, I believe that elves and dwarves cannot reproduce, whereas many other systems do not uphold this belief.
For other races, use approximate longevities to find equivalent modifier. So, for the above example, if the female is a half-elf and the male is an elf; the chance becomes: 2 x (12) + 10 - 5 = 29% If protection is used (eg a sheepskin condom), the chance of pregnancy is halved.
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Poison Rules

Poisons are frequently used in AD&D but the rules are often different and unrealistic. The following rules attempt to account for poison realistically and simply, and to do away with the ever-popular type F poison that gives you a saving throw chance to survive.

Poison Effectiveness:

When the poison is applied, make a percentile roll for effectiveness (which is a percentage of the total damage inflicted by the poison). This percentage is adjusted for method of application; if the poison is ingestion only then splashing the vistim will have little effect, but if it is a contact poison, then although splashing will work, injection (via an arrow head or blade) will be more effective.

Poison Damage and Lethalness:

The poison must have an damage based on how effective it is at harming the victim: eg: A good lethal poison could do 3d8 hp damage (enough to kill any 0th level human without a problem). A fantastically lethal poison could do 6d8 hp damage; enough to kill almost any low-level adventurer on a failed save.
Thus the damage done by a poison is always variable.

Saving Throw:

A saving throw ensures that only half damage is sustained.

Sustaining Damage:

Damage from a death-dealing poison, can be taken at any rate chosen by the DM, from 1 hp per turn for a slow acting poison, to 1 hp a round for a pretty quick poison to 10 hp a round for a very lethal poison, depending on the effect desired. For paralysing poisons, there are two options:
1. That the paralysis is instantaneous and lasts for as many rounds as the effective damage.
2. That it does paralysing damage, taken at a rate chosen by the DM (see above for suggestions) and in this time the character cannot perform anything even vaguely complicated like casting a spell or defending themselves.

Random Poison Table (1d10):

1 Paralysis 1d6 rnds
2 Paralysis 2d6 rnds
3 Paralysis 2d4+2 turns
4 Paralysis d4 turns + 2d4 damage
5 Poison 1d8
6 Poison 2d8
7 Poison 4d8
8 Poison 1d6
9 Poison 2d6
10 Fast-acting (doubles speed) Reroll

Method of Application Table (1d6):

1. Ingested
2. Splashing
3. Injected
4. Inhaled
5. Injected
6. Two of these: Reroll twice.

Thus, to apply a poison, first roll the percentiles for effectiveness (include bonuses and penalties for method of application) and then roll the damage. This damage is then multiplied by the percentage to get the total damage that the victime will sustain. Once done, the victim makes it's save vs poison and then takes the appropriate damage at the rate specified by the DM.

Example: Zeroth fires a poison tipped arrow at an orc, hittin it successfully and doing 3 points of damage (for the arrow). He rolls for the effectiveness of the posion and gets 36%. The DM rules that poison on an arrow head is a pretty effective method of application for an injecting poison and grants him a 45% bonus, totalling his effectiveness at 81%. The poison was a 3d8 poison, so he rolls his damage and gets 13. Multiplying this by his effectiveness (and rounding all fractions up) he gets 11 hp damage. The orc then rolls his save vs poison and passes and so takes 6 hp damage. The DM states that the poison is fast-acting and does 2 hp damage per round.


These rules may be a little complicated, so the effectiveness could easily be left out to no detriment to the game at all. Also, the saving throw could be modified such that a successful save means the victim resists the poison and so takes damage at half speed. In fact, there are many ideas governing this area, but as long as you are happy with the rules you are using, that's what's important. Or so I keep telling myself.
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Casting Priest Spells

These rules were written before I discovered the PLAYER'S OPTION: Spells and MagicTM book, which is far superior and I highly recommend it as it has completely revamped our spell system so it is far more flexible. However, if you can't buy it and want to be a little more flexible, this might work. These rules, by the way, are not at all new or original so don't be surprised if you're already using them.

Priest spells are divinely given and hence do not have to be specified each day. A priest may use up to his/her spell limit and no more: any spell can be used more than once if their level and allocation allow it.
For example: Tasha is permitted to cast 5 first level spells per day. Thus she can cast up to five cure light wounds if she wishes, provided she has cast no other first level spells.

Spell Level Transferral:

A priest can also sacrifice any spell of one level for a spell of a lower level.
E.g.: Tasha can also cast one third level spell per day. However, she realises that she needs to heal a party member and cannot do so with any of her third level spells; so she sacrifices her one third level spell for another first level spell, in this case, cure light wounds.
A lower level spell cannot be sacrificed for a higher level spell.
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Casting Wizard Spells

Once again, these rules have been made obsolete by the Spells and Magic book, but they're okay in their own way.
A wizard no longer has to state which spells he is memorising each day. It is assumed that s/he memorises all of them, and can use them to his/her full spell quota for the day. However, each spell, once cast, is lost from memory and cannot be cast more than once unless the wizard consults with his/her spellbook. The spell quota cannot be exceeded: once all spells have been cast to that limit, the others fade in the mind.

Spell Level Transferral:

See above. A wizard can sacrifice a spell of one level to use a spell of a lower level, but then cannot cast that higher level spell.
E.g.: Marcus can cast two level four spells. However, in a given situation, he requires a third level spell but has cast his full quota of them. So he sacrifices one of his fourth-level spells for one of his third-level spells. For the rest of that day he only has access to one fourth-level spell.
A lower level spell cannot be sacrificed for a higher-level spell.
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The Assidilent Character Class

This character class was one developed by Rachel and myself for her character arkh-Shamier'yv (effectively our playtest character). The other character classes did not fit the style of character she wanted to take at all, so in the end we decided to develop our own. The name is a combination of the words 'diligent', 'vigilant' and 'assiduous' (Rachel came up with it).

The Assidilent: An assidilent is a watcher, a caretaker almost, a gatherer of knowledge and languages. They are usually wanderers, quite often pacifists, or certainly not fighters, people with a thirst for knowledge about everything. They cannot cast spells (unless multi-classed, obviously), cannot specialize like fighters and can only do a few of the things that Rogues can do. They can take Non-Weapon proficiencies from the General, Priest, Wizard and Rogue groups (paying double for Fighter group proficiencies) and can use any weapons they so desire.

Requirements: None.
Prime Requisite: Wisdom 12.
Hit Points: 1d8/lvl.
Hit Points after 9th lvl 1 hp/lvl
Thac0: 2/3.
Race Restrictions: None.
Religion: Any.
Weapon Proficiencies: Initial: 2
Increase: 1/4
Non-weapon Proficiencies: Initial: 4
Increase: 1/4
Abilities: DN, RL, HIS as table 19, DMG.
Saving Throws: As Cleric.

XPs Table:
Level: Experience Points Required:
2 1,100
3 2,200
4 4,400
5 11,000
6 22,000
7 44,000

If anybody decides to use this character class, I would love to here about the character and how this class works within your world. Get me at: Rain or anywhere else if you can find me.
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[The Campaign] [Judas' Game] [Other Personas] [The Dungeon] [Kline Syndrome] [Transcript] [Roleplay Ramble] [The Banana Zone]