Roll d% to see if you rise as a Ghoul

One of the things has always bothered me about D&D is how so much of the fluff is segregated from crunch.

"You can fail a resurrection spell and someone back as zombie? That sounds -- oh wait, there are no rules for that."

"You can combine two animals into an abomination like an Owlbear? That sounds -- oh wait, there are no rules for that."

"People can spontaneously rise as undead? That sounds -- oh wait, there are no rules for that."

The last one brings me to today's post. I've been thinking on-and-off about developing my own retroclone-esque roleplaying game (probably something that'll end up an Owlbear-tier combination of GURPS, AD&D, 5e, and Mutants & Masterminds with a dash of Fighting Fantasy but I digress). 

One idea that keeps rattling about is a subsystem that allows the DM (or players, whatever) if a PC can rise as an Undead. Being a spy (or a voyeur) can make your PC rise as a Spectre. Party members near an evil shrine or temple may rise as Zombies. Eat any bit of the flesh of a sapient and you have a higher chance to rise as a Ghoul. Think of it as an earnest if somewhat misguided attempt to make those old adventure hooks into spontaneous self-perpetuating rules constructs. Anyway, on to the rules:

When the character dies, roll d% or 1d100. If the result is higher than the chance of rising then nothing happens. If it is equal to or lower than the percentage then the character rises as a Ghoul  about 24 (4d12) hours after his death. 

The base chance of a dead character rising as a Ghoul is 5% modified by the table below. Modifiers are cumulative. The final percentage cannot be less than 0% or greater than 100% unless you want to homebrew some crazy results.

The dead character . . .	% Modifier
. . . was Evil (if using an Alignment subsystem)	+10%
. . . was Chaotic (if using an Alignment subsystem)	+5%
. . . was Good (if using an Alignment subsystem)	-10%
. . . worshiped a god or power related to death, gluttony, Ghouls, or hunger	+10%
. . . had more than two character levels or Hit Dice (if using a level/Hit Dice subsystem)	+1% for each level/Hit Die beyond 2
. . . unknowingly ate the flesh of a sapient creature within the last 48 hours	+1% and additional +1% for every 5 pounds of sapient flesh consumed
. . . knowingly ate the flesh of a sapient creature within the last 48 hours	+10% and additional +1% for every 5 pounds of sapient flesh consumed
. . . killed a sapient creature within the last 48 hours specifically to eat it, but was in a state of extreme hunger and/or had no other food	+15%
. . . killed a sapient creature within the last 48 hours specifically to eat it, but was in a state of hunger and/or had little other food	+25%
. . . killed a sapient creature within the last 48 hours specifically to eat it despite having plenty of ordinary food	+45%

Here are examples of the system in practice:

Hogni Redbeard was a Lawful Evil (+10%) thief-acrobat-rogue with 3 Hit Dice (+1%). After becoming a devotee of The Great Maw, god of hunger (+10%), he adopted serial killing and cannibalism as hobbies. He kidnapped a Halfling merchant then killed him to make a stew (+45%). In the last 48 hours the only sapient flesh he managed to eat consisted of two hearty meals of Halfling stew which together added up 15 pounds (+10% for knowingly consuming, +15% for the amount consumed) before a band of vigilantes busted in and killed him. There is therefore a 96% (5% + 91%)chance that 4d12 hours after his death he will rise as a Ghoul.

Brother Magnus was a Neutral Good (-10%) Human 5^th-level (+3%) cleric. Trapped underground and without food, he stumbled into the storage room of some Goblins. Inside, he found some bundles of preserved meat. He ate 5 pounds of the meat without realizing that it was Elf jerky (+1% for unknowingly eating, +1% for the amount). Suddenly, two Hobgoblins appeared and attacked! Magnus was victorious but one of the dying Hobgoblins taunted him by revealing the nature of Magnus’ last meal. Distraught but still hungry, he grabbed some more of the meat and continued on his journey to find an exit from the underground hell. Although hungry, he only managed to eat another 5 pounds of Elf jerky (+10% for knowingly eating, +1% for the amount) before his moral repulsion overpowered his gnawing hunger. Alas, in his sleep a leak of toxic gas suffocated him. There is therefore an 11% (5% +6%) chance that he will rise as a Ghoul in 4d12 hours.

Now of course, there are some issues that I still have with my concept. Do the same rules apply to carnivores? What does this mean for creatures like Gnolls that deliberately eat sapients on large-scale? Are they basically guaranteed to rise as Ghouls? Should a mammalian humanoid incur the normal penalties for eating the flesh of sapient avian, insectoid, or reptilian humanoid or should they be diminished or waived? What about eating the flesh of sapient non-humanoids like Awakened Cows, Beholders, and Sphinxes?

I should have plenty of time to iron out the finer details later but a start is a start.