Magic Hit Dice - A Short Post

This is going to be a very short post outlining the casting mechanic I use in most of my games. It's been referenced previously (in this rambling post concerning hit dice in 5e and O5R), and one iteration appears in my poorly conceived b/x sorcerer class.  As stated in previous pots, this mechanic was partly inspired by the GLOG magic dice system (about which you can read more here, under the section entitled Casting Mechanic). The key difference here is that magic dice are the same as hit dice, and this slots into a larger framework where hit dice are a resource that must be managed.

Courtesy Adobe Stock.

Wagering Inner Power

Casting a spell involves an investment of one's own personal energy: the caster must roll a number of their own hit dice appropriate to the spell (usually this equates as one die per spell level). A roll of four or higher means the die is "spent", and cannot be regained until after a good night's sleep. 

The total value of all numbers ruled will dictate the effect of the spell: this could be the total damage caused by a fireball, or it could dictate the duration, range or other effect as described. A more thorough description of spells and spellcasting will follow soon!

Note that PCs with a larger hit die will do more damage/ create more intense spell effects but they are also more likely to expend hit dice while doing this. PCs with smaller hit dice are more likely to retain their hit die/dice after casting, although their spells may be weaker. There is another cost to this, too...

Spell Failure

As with GLOG magic dice, there is a chance of spell failure when one starts to use more powerful magic. This is represented mechanically by the rolling of double (or triple or quadruple ones...)

• Double ones: fizzle. The spell fails. An action is wasted, but there are no further effects.
• Triple ones: backfire. Instead of the intended target, the spell now effects the sorcerer. Area effect spells will now centre on the sorcerer instead of the intended target. For utility spells, the DM is allowed to be creative (what would a backfired arcane lock do?) 
• Quadruple ones: as above, but additionally the sorcerer is cursed (thank you, goblin punch)
• Quintuple ones: as above, but additionally the sorcerer receives a superficial mutation. All mutations manifest after a full night's sleep. 
• Sextuple ones: blursed. As above, but the sorcerer must also re-roll all dice (the spell backfires, the sorcerer is cursed and receives a mutation, then the sorcerer effectively re-casts the spell)
• Septuple (or more) ones: So bad it's good. All dice are re-rolled ad the sorcerer receives one fate/inspiration/hero point (if used). I mean, the odds are 1 in 16,384... so...

Casting without Hit Dice

If the caster has run out of hit dice, they may still cast spells, but take the resultant roll as damage to their hit points. Additionally, any ones rolled will inflict that number points in damage to their casting stat.

~

Future posts that I will link from this page will include a more detailed spell failure table, curses and mutations, as well as a comprehensive spell list.