House Rules and Interpretations

House Rules and Interpretations for OSE

Bend Bars/Lift Gates
We are about to run a couple of modules that have traps or other things that rely on a bend bars/lift gates mechanic like the one presented in 1st edition AD&D and 4th ed. Hackmaster (yes, I know it is really first edition).  Anyway, the table we intend to use looks something like this.  The sequence is +1,+1, +2, +3, +4, +4, +5, +5.

Strength
Chance of Success
<=7 
0%
8-9 
1%
10-11 
2%
12-13
4%
14-15
7%
16
11%
17
15%
18
20%
19+
25%


Potion of Gaseous Form
The character operating under the effects of a potion of gaseous form can choose to end the effect at will.  The potion can allow removal of a helm of alignment change


Experience Points for Entertaining Deaths 
A “self defenestration” is worth 100XP.  
Getting killed by a polymorphed 8th level wizard disguised as a flying cave bear only gets you 25XP.  
Killing yourself by drinking an unknown potion in the middle of a major combat and failing your save against poison is worth XP equal to your PC’s HD plus one special ability bonus.


Rolling up Characters
Roll 4d6 for each attribute and throw out the lowest die.  Arrange the pool of scores as desired.  
If a first level character rolls a 1 or a 2 for initial hit points, they get a one time bump to 3 hp out of mercy (before Constitution adjustments up or down)
A cleric may be able to cast cure light wounds if the cleric is role played to stay in the particular favor of his/her diety.
A magic user or illusionist starts with Read Magic and three other spells chosen by the player to put in his/her spell book.  A caster is still limited to the number of spells cast per day equal to the advancement table.  


Open Doors
The Open Doors check works on stuck doors without a crowbar.
Locked doors can be forced open using a crowbar with a successful open doors check. 
A failed Open Doors check equates to loss of surprise for any encounter on the far side of the door.  
Even if you don't have a crowbar you can bust down a stuck or locked door with enough raw strength checks and time, but forget about any chance of surprise and expect to draw additional wandering monster checks.
A typical stout oaken door with iron bands is 35hp and can be treated as an AC9 opponent for purposes of busting the door down using weapons such as axes or clubs.
Applying fire to a door requires 1 flask of oil per round.  Again, 35hp is a general target for how much damage the door/frame/hinges/latch/lock require before something gives way.  This generates a lot of smoke and heat and again negates surprise and will likely draw wandering monsters.


Zero Hit Points
At zero hit points a character is unconscious and will continue to lose 1 HP per round until someone spends a full round tending to the wound.  
A character that reaches -10 hit points is permanently dead.  
Any magical healing that takes place must offset the negative value, otherwise the PC is still in a dying state.
At -6 hit points, some kind of permanent scarring or defect will remain no matter if magical healing is used.  Such disfigurement should relate back to the cause of the wound that drove the PC’s hit points to zero or below zero.


Weapons Proficiency
Weapons proficiency from OSE Advanced is in use.


Splash Table
The Splash Over/Under mechanic is replaced with a d8 roll.  The throws are assumed to land within 5’ of their intended target unless there is something that prevents it (such as a pit, wall, etc.)
 
1 = short left
2 = short before
3 = short right
4 = left
5 = right
6 = long left
7 = long over
8 = long right
* Order adjusted for consistency from AD&D 1st edition


Potion Miscibility Table
Mixing two or more potions together will have the results as outlined in the AD&D 1st edition DMG pg. 119.  The GM will make this percentage roll secretly.  Players must sip or drink the concoction to discern the results.  Once the results are known, there is no guarantee that future potions of the same variety will admix in the same manner as there are different formulae to manufacture a potion.


Adding Spells
There are three ways that a caster can add spells to his/her spell book and/or repertoire according to the OSE Rules Tome and OSE Advanced Fantasy Supplement.
Mentoring - as stated in the rules, this is fairly straightforward.
CopyingUnearthed Arcana pg. 80 says that using a Read Magic spell will enable learning spells from another mage’s spell book and that the learning process requires 2d4 hours of study per level of the spell.  Should a character successfully copy a spell, future copies only require 2/3 the amount of time to transcribe the spell as the original amount of time taken.
Research.  The rules from the Adventurer Conqueror King System (ACKS) and The ACKS Heroic Fantasy Handbook (Custom Spells pg. 207) provide guidelines for researching new spells and potential build points and trade offs to achieve balance.