Over on the Google Plus fellow traveller Paul Schaefer asked me an interesting question and with his permission I'm going to answer it here rather than in a private discussion:
As a Basic D&D DM, since it has race as class, what do you do if a player wants to play a race but also wants to use a weird class from another source such as Arduin, Field Guide, Arcanum, or what have you?There are several strategies a BX Dungeon Master can employ when a player makes this sort of request. Which one you use depends largely on your comfort level and your vision for the campaign.
Do you just sort of eyeball it, try to balance the race and class abilities?
Option 1: Just Say NoAs I was just discussing with Jeffro Johnson, there's nothing wrong with insisting that this is a game with a specific ruleset and all dwarves, elves, and halflings follow the same simple rules. You've got to run the darn thing, so you're responsible for deciding when the rules as written will bend. Rather than go the typical route of class/race editions, where you hang your hat on being a Halfling Sewer Assassin or Dwarf Poisonmage or Elf Tree Idiot, the way one distinguishes oneself in such a game is to play the Best Damn Halfing Ever, The Most Memorable Dwarf We Ever Encountered, That One Elf Who Didn't Suck, etc.
Option 2: Add Race to the ClassUnder this scheme the class is the basis for the rules pertaining to the character. Adding the race selection only grants the character two things, 1) the items listed under the relevant SPECIAL ABILITIES on pages B9 and B10 and 2) the race-based saving throws.
Modify they experience needed for second level for the class using the chart below, then recalculate the rest of the chart.
Demi-Human Costs for Weirdo Classes
Halfling ... +150xp
Dwarf ... +250xp
Elf ... +250xp
Elf would be little higher than dwarf, but I'm assuming the level racial caps (H9, E10, D12) are in play.
You can use this for the standard classes as well, if you need something like a Dwarf Cleric or Halfling Thief. In fact, since it's so popular an option, here's my proposed chart for the latter combo.
1st level ... 0xp
2nd level ... 1,350xp
3rd level ... 2,700xp
4th level ... 5,400xp
5th level ... 10,800xp
6th level ... 21,600xp
7th level ... 43,200xp
8th level ... 80,000xp
Note that I rounded the XP amount for 8th level down slightly, as in the original chart.
This option ought to work well if you've got a clear understanding of the new class and how it will impact your game.
Option 3: Add Class to the Race
Add this amount to the figure for the dwarf, elf, or halfling in question and recalculate. For example, say you got a player who wants to be a Halfling who is also an Arduin-style Merchant. According to the original Grimoire, a Merchant needs 2,250 XP for second level, or 1,050 XP over the thief horizon. The XP chart for a Halfling Merchant would look like this:
Halfling Merchant XP Chart
1st level ... 0xp
2nd level ... 3,050xp
3rd level ... 6,100xp
4th level ... 12,200xp
5th level ... 24,400xp
6th level ... 48,800xp
7th level ... 97,600xp
8th level ... 200,000xp
The result is a character that follows all the Halfling rules and gets all the special abilities of a Merchant. Note I used a little judicious rounding for 8th level, just like the normal halfling chart on page X6. Only I rounded up because I'm a jerk.
You may also want to drop some features of the base to bring down the XP totals a bit. I'm thinking particularly of curtailing the ability to wear heavy armor (halflings in plate mail have always irked me anyone), the wide weapons choices, and possibly elvish spellcasting. Do the math for second level as above, then modify according to this handy-dandy chart I just made up:
Discounts for Surrendered Abilities
No Plate ... -50
No Plate or Chain ... -100
No Armor ... -200
Restricted Weapons ... -75
No Spells (elves only) ... -1,000
By "limited weapons" I mean something comparable to the cleric's lame selection. If it's more like a magic-user's lame selection, double the discount. Note that those numbers may seem small, but they will really add up as the XP needed doubles from level to level.
This option will probably end up costing the PC more in terms of XP needed for progression. But if its a weird class and you aren't sure how its going to interact with the BX demihuman rules then it may be a good thing to put the brakes on a little bit.
Option 4: Build it From Scratch
Paul Montgomery Crabaugh's article "Customized Class: How to Put Together One-of-a-Kind Characters" from Dragon #109 (pages 8, 10-13*) is my go-to source for puttering with BX classes. In recent years at least two people have put work into improving Crabaugh's method. One is my buddy Nick on his blog Of Dice and Djinn. He's also built a crapton of cool classes using his system. Perdustin over at Thoul's Paradise has also written at least four articles tackling the subject. Both those blogs have great titles, by the way. (True fact: I almost called this blog "The Half-Orc's Lair," quoting from Uncle Gary for the tagline "Half-Orcs are boors. They are rude, crude, crass, and generally obnoxious." (DMG 16) But then I realized that would only encourage me to act like a jerkbutt on the internet. So I put my real name at the top instead.)
Option 5: Go Find Your ClassThis option eschews fiddling with XP and instead turns the whole problem into a quest. "You want to be a dwarf alchemist? Fine. You start out as a regular, well-adjusted dwarf. Now find an alchemist who will take you on as an apprentice." This option works really great if you're playing in a big sandbox. Just pick a few places where the PC might be able to get the training they want, then sprinkle the map with a few more places that have leads for the PC. Then once they find an alchemist (or whatever) willing to take them on, the PC has to finish another adventure to Prove They Are Worthy.
At that point, award the PC with the abilities of a first level whatever-it-is. Then every time they gain a new level in their regular gig they also have to complete a side quest assigned to them by Master Yoda to also level up in the new class.
Option 6: Ignore the Problem
Not a terrible option for games with a good PC body count. An elf with berserker abilities/berserker with elf abilities isn't that much harder to murder at 1st level than an elf or a berserker. At least if you try hard enough.
*Page 9 of Dragon #109 is a full page ad for the global throwdown simulator Supremacy. Never played it, but I always loved the fact that it came with tiny plastic mushroom clouds.