My group are just starting to play-test this concept, specifically to address the lack of a magician in their party. Should a player be forced to roll up a new character to fill a vacancy, or can his existing character branch out into a new skillset? I run Second Edition, but the following was written with 3E in mind. Constructive feedback is welcome.

Multi-classing in Hyperborea

Instead of gaining a level in his current class, an eligible PC can opt to start a new class.
— A PC must meet the attribute, alignment, and roleplayting requirements of all classes.
The PC’s XP total is reduced by the minimum needed for the current level.
— Example: A 4th-level purloiner with 21,830 XP is eligible to train for 5th level. Instead, he opts to train in a new class. His XP total is reduced by 10,000 (the minimum for a 4th-level purloiner), leaving him with 11,830 XP in that class.
The PC thereafter will maintain a separate XP total for each class. The new class starts at 0 XP. Awarded XP will be divided equally amongst all classes.
— At the referee’s discretion, XP might be divided differently if the abilities of one class were neglected.
— Any +10% XP bonus applies only to the class(es) for which the PC has scores of 16+ in the prime attribute(s).
The PC gains hit points only when the highest-level class increases, using that class’s hit die type.
— Example: A 2nd-level fighter has 2d10 hp. A 2nd-level fighter / 2nd-level thief has 2d10 hp. A 3rd-level fighter / 2nd-level thief has 3d10 hp. A 4th-level fighter / 5th-level thief has 4d10 + 1d6 hp.
— A PC may roll his highest hit die type for daily hit point recovery.
The multi-classed PC must abide by the armour and shield restrictions of each class when using that class’s functions.
— Example: A multi-classed fighter/thief can wear heavy armour and fight, but any attempt to climb or move silently will fail.
— Example: A warlock can cast magician spells in medium armour, but a multi-classed fighter/magician attempting to do so stands a 2-in-6 chance of spell failure.
— N.B.: See exception below for sorcerers with multiple classes within the same division of sorcery (i.e., thaumaturgical or ecclesiastical).
The PC can use weapons from any of his classes’ favoured weapons lists.
— The lowest unskilled weapon attack penalty applies when wielding unlisted weapons.
The PC’s base saving throw (SV) score is that of his highest class level. Saving throw modifiers from each class apply but do not “stack”.
— Example: A multi-classed purloiner/magician gains a +2 bonus to device, avoidance, and sorcery saves, but not a +4 sorcery bonus.
A multi-classed PC may use the highest fighting ability (FA), turning ability (TA), and casting ability (CA) of his classes.
Duplicated class abilities do not “stack”.
— Example: The barbarian and the thief both have the agile ability. A multi-classed barbarian/thief receives only a single +1 AC bonus.
— Example: The barbarian and the thief both have the move silently ability. The higher chance-in-twelve applies.
— Example: The ranger and the scout both have the alertness ability. A multi-classed ranger/scout receives only a single −1 surprize bonus.
— Example: The magician and the cleric both have the scroll use ability, but these abilities apply to different spell lists. A multi-classed magician/cleric can use scrolls from either the magician or cleric spell lists.
The number of spells known by a multi-classed sorcerer is the total of all classes.
— Example: A 4th-level purloiner / 1st-level magician knows 8 cleric spells and 3 magician spells.
Multi-classed sorcerers who cast either thaumaturgical or ecclesiastical spells from different spell lists are treated as if all classes were the same.
— The number of spells cast per day is the total from all classes. Bonus spells from high intelligence or wisdom are counted only once.
— The sorcerer may prepare spells freely from all available spell lists within the same division of sorcery (i.e., thaumaturgical or ecclesiastical).
— Armour restrictions are those of the most favourable class.
— Example: A 4th-level druid / 3rd-level cleric can cast 5 level one and 3 level two spells per day (plus bonus spells for high wisdom, if applicable), at CA 4 capacity. Each spell may be prepared from either list of spells known by the PC; the sorcerer could choose 1 cleric spell and 7 druid spells if desired. Since clerics are permitted heavy armour, druid spells could be cast whilst so equipped.
Multi-classed sorcerers who cast both thaumaturgical and ecclesiastical spells are treated as members of different classes.
— The number of spells cast per day is the total of each class separately, with bonus spells for high intelligence and/or wisdom added as applicable.
— The sorcerer must prepare spells separately from each available spell list in different divisions of sorcery (i.e., thaumaturgical or ecclesiastical).
— Armour restrictions apply to each class separately.
— Example: A 4th-level necromancer / 3rd-level cleric can cast 3 level one and 2 level two necromancer spells and 2 level one and 1 level two cleric spells per day (plus bonus spells for high intelligence and/or wisdom, if applicable), all at CA 4 capacity. Each spell must be prepared separately from the respective spell list. Though clerics are permitted heavy armour, a 3-in-6 chance of failure would apply to any necromancer spell cast whilst so equipped.
— Example: Let’s break the system by combining both scenarios. A 12th-level shaman (druidic/necromantic) / 9th-level warlock (fire lord) can cast 2 spells each of levels one–three and 1 spell each of levels four–six from the druid spell list (plus bonus spells for high wisdom, if applicable). He can cast 4 spells each of levels one–three and 1 spell each of levels four–six (plus bonus spells for high intelligence, if applicable, counted only once), in any combination, from either the necromancer spells in his shaman spell book, or the pyromancer spells in his warlock spell book. All spells are cast at CA 12 capacity. Any of his thaumaturgical spells (i.e., necromancer or pyromancer) can be cast in medium armour, as that armour type is permitted to warlocks. However, a 2-in-6 chance of failure would apply to his druid spells, since medium armour is not permitted to shamans, and warlocks do not cast ecclesiastical spells.
Under no circumstances does a PC receive additional starting gold when beginning at 1st level in a new class.
— If entering the magician class (or one of its subclasses), then the PC must prepare a spell book and inscribe spells therein at the requisite cost.

Last edited by DMPrata (10/22/2024 9:48 pm)