The main issue with playing BECMI is that race and class are not separated. Even though the amount of classes when including all the supplements is quite big, the fact that demihumans have a racial class, and there’s no Multiclassing or Dual classing makes the perception of character creation quite limited. I would argue that the addition of the skill system adds all that versatility back, but sometimes you just want to wear armor and cast fireball and be a Lupin at the same time. Most players are going to be taking a single class, but for the truly unique visions, I have the following rule system.

Humans are still the default assumption and have access to all classes. The racial class is the default assumption for any demihuman. However, if a demihuman character wishes to take a class that is not their default race class, the following chart is consulted:

RaceStrIntWisDexConChrHDXP
Dwarf+100-1+1-10+10%
Elf0+1-10000+15%
Gnome-10+1+1-100+15%
Halfling-100+1000+15%
Lupin+1-1-10+10+1+30%
Rakasta00-2+200+1+30%
Tortle-1+10-3+300+15%

The stat adjustment is to the final score, the HD adjustment is to the type of dice used to roll hit point. For example, a Lupin Thief rolls a d6, not a d4. And the XP column is the adjustment to the XP requirements needed to gain a level. The character retains their physical abilities, like infravision, immunities or bite attacks, but looses knowledge based skills, like halfling forest hiding or detecting secret doors. Saving throws are based on class that is taken.

Muticlassing

A character has a two options for multiclassing that fits withing the power progression of BECMI.

The first one is they can take the ‘Paladin’ approach. This means you choose a Primary and Secondary class, You get the secondary class for ‘free’ but at a third of the rate at your primary class. You must take the most restrictive armour and weapon limitations of your two classes. Your hit points and hit rolls are defined by your primary class. Add +5% to the XP needed to attain a level. This can be offset by the XP bonus for having high stats in your primary class (i.e. the XP bonus given to a fighter with high strength, for example.) This character type will experience ramifications that take place within the campaign. Since the character has chosen a path that doesn’t fit within society there will always be trouble. For example, a Cleric sub Thief will always be seen as shifty by their church and never be able to truly rise in the hierarchy and also will always be seen as a religious freak by their underworld peers. This character is walking a middle path.

The second option is the ‘two guns’ approach. This means the character has two distinct classes and will advance equally in both until reaching level 12. After that, for each level gained, the player will choose which class to advance for each level gained. The character has to make the highest XP amount to level up between the two classes chosen plus 50%. The dice rolled for hit points is averaged between the two required for each class. You attack with the best THAC0 between the two classes, best saving throws, and gain the best Weapon Mastery advancement between the two as well. This character has less social restrictions in the campaign as they are truly leading a double life and are multi-talented. A dual class Cleric/Thief may have been a thieving scamp as a youth, but saw the light and joined the church properly with only the occasional sneak while adventuring to keep his Thieving skills sharp. The power of the dual classed is offset by slower advancement and a lower peak in ability.

I don’t allow three or more classes at once. And I don’t allow Dwarven Magic-Users. This system is for players who have a very specific vision of what they want to play and to give them the tools to play that character withing the confines of BECMI. The XP penalties for leaning into this system are cumulative. An Elven Cleric/Thief duel class will add the +15% for their race as well as the +50% for dual classing. To reach second level it will take 2475 xp. When he achieves 12th level he will have earned 858001 xp. For comparison, a single class thief with that xp will be 14th level and a single class cleric will be 15th.

Of course any of the weird class types from the Gazeteers and Creature Crucibles are able to be chosen. The charts I use for Humanoids will be added later. I will be adding some new classes as well, like a fleshed out Rake, Bard, and Druid classes.