In Keyword Design, I use a single word as inspiration for a mundane item, a magic item, a feat, a spell, and a class option. Today’s word is “leech” as suggested by Nick V.

Now I’m not qualified to say this in any way, but leeches make more sense in a fantasy setting than in reality. They’re like giant parasites, in line with the fantasy trope that the smaller something is in our world, the scarier it is when it’s oversized in a fantasy world.

Leeches are best known for their suction cup mouths and thirst for blood. I am qualified to say that first we had the creature, then we had the verb for slowly profiting off a situation. Mixed in there somewhere is medicinal leeches. So there are a lot of directions I can take leech-related options.

LEECH

TYPE	NAME	DESCRIPTION
Mundane Item	Healing Hirudo Jar	A jar of medicinal leeches for treating disease.
Magic Item	Coin Syphoning Gloves	Touch attack steals coins.
Feat	Throttling Grapple	Choke the life out of the target of your grapple.
Spell	Bloodsucking Wall	Thorns drain the blood of anyone who tries to pass.
Class Option	Investigator talent: Disseminating Study	Pick apart your opponents’ defenses as you study them.

New Mundane Items
HEALING HIRUDO JAR
Cost: 50 gp Weight: 2 lbs
A certain contingent of healers believes that anything with medicinal value should be exploited, no matter the civility of the method. These healers have no issue applying blood sucking parasites to diseased patients if the end result is positive for the patient.
Applying a medicinal leech from a healing hirudo jar is a full round action and requires a DC 10 Heal skill check. After 8 hours with a medicinal leech applied to the skin, a patient gains a +1 circumstance bonus to Fortitude saves to resist disease. A patient can have a number of medicinal leeches applied at one time equal to their HD, but after 8 hours a patient must make a Fortitude save or become sickened for 1 hour. The DC of this equal to save is 10 + the number of leeches currently applied.
Removing a medicinal leech alive requires a DC 10 Heal check and a standard action per leech. Failing this skill check or removing the leech without making a skill check kills the leech and deals 1 damage to the patient. Dealing 1 damage to a medicinal leech kills it without harming the patient. A medicinal leech that has been removed alive can be replaced in the healing hirudo jar for later use.
A healing hirudo jar contains 25 medicinal leeches.

The first leech option is the most literal. Even though hirudo medicinalis is a species of leeches still used as “medicinal leeches“.
I know we’re talking about a fantasy world with medieval levels of technology (where mana wastes haven’t limited the use of magic and force the advancement of technology to the gunpowder age), but I still didn’t want to make medicinal leeches a purely beneficial option. So you can wear them (you can wear a lot of them even) but at the risk of getting sick.
I had an issue with terminology here. I didn’t want to call the person with leeches on them the wearer or user, so I went with patient even though there’s no precedence for the term.

New Magic Item
Coin Siphoning Gloves
Aura moderate conjuration; CL 9th; Slot hands; Price 4000 gp; Weight —
DESCRIPTION
These thin leather gloves have a glossy finish that makes them appear more slippery than they feel.
Three times per day on command, the wearer can make a touch attack targeting an attended coin pouch. On a successful hit, 1d6 coins from the touched pouch teleport into the wearer’s coin pouch or other designated container on the wearer’s person, starting with the most valuable coins.
Thieves and similar scoundrels are particularly adept with coin siphoning gloves. A wearer with the sneak attack ability rolls 1d6 plus a number of additional d6s equal to the number of sneak attack dice they roll to determine the number of coins they siphon.
The wearer must wear the gloves continuously for 24 hours before activating this ability.
CONSTRUCTION REQUIREMENTS
Craft Wondrous Item, teleport; Cost 2000 gp.

This magic item should not have taken as long to develop as it did. I thought that letting rogues steal additional coins was a fun bonus ability for these gloves and tying it to sneak attack made sense. However, I was having so much trouble wording that you roll a number of d6 equal to your sneak attack dice +1d6. I crowdsourced the network to make sure my wording was clear and eloquent and it was pointed out that my original wording made it sound like the wearer deals sneak attack damage to their target and then steals a number of coins equal to the damage dealt.
I’m still not crazy about the wording and might come back and edit it if I can find any precedent for how such an option would be written.

New Feat
THROTTLING GRAPPLE (Combat)
The longer you grapple, the tighter your grip.
Prerequisite: Dex 13, Heal 5 ranks, Improved Grapple, Improved Unarmed Strike.
Benefit: Whenever you successfully maintain a grapple and choose to deal nonlethal damage, you deal additional nonlethal damage equal to the number of rounds you have consecutively maintained the grapple.

The feat was the option that took me the longest to design. I flirted with the idea of a vampiric metamagic feat but that felt a bit too words of powery and I already have a few blood-related options. Grapple offered an interesting design direction. As someone who has been in a chokehold, I can say that it isn’t the damage the move is doing as much as it is the building concern over the inability to breathe.

New Spell
BLOODSUCKING WALL
School necromancy; Level antipaladin 4, bloodrager 6, magus 6, sorcerer/wizard 5, witch 6;
Casting Time 1 standard action
Components V, S, M (a leech that died of starvation and a rose stem)
Range close (25 ft. + 5 ft./2 levels)
Effect wall of bloodsucking brush, up to one 10-ft. cube/level (S)
Duration concentration + 1 round/level
Saving Throw none; Spell Resistance no
You create a long, tall, brambled shrub. On closer inspection, each of its thousands of apparent thorns puckers at the tip like a tiny suction cup.
This spell works like wall of thorns, except you gain the damage dealt as temporary hit points for as long as you concentrate on the spell, plus 1 round/caster level.

The last spell I designed was Bloodsucking Contract, and I almost didn’t replace it because I copied and pasted the ‘Merika content as a template.  
So, a wall of thorns, but shorter, arcane, and vampiric. And that’s it. It’s as on theme as it is on the nose.

New Class Option
INVESTIGATOR TALENT: DISSEMINATING STUDY
Some investigators put their analytical minds to work fastidiously learning their enemy’s weaknesses to exploit.
Disseminating Study
Prerequisite: Investigator 5th level
Benefit: The investigator can study his opponents’ defenses, gradually pick them apart. The target of his studied combat takes a -1 penalty to AC, CMD,  and saving throws against the investigator’s attacks and abilities. Every round the investigator continues to study the target, this penalty increases by 1.

I usually build more elaborate class options, but 1. I’ve been spending most of my time on this article writing a huge kineticist option that just wasn’t working (more info below), and 2. Disseminating Study does everything I want a leeching investigator to do. The studied combat ability is great, but it lasts a number of rounds or until you hit without giving any additional benefit for intentionally delaying your attack. Other than the double dip of standard studied combat giving the inquisitor a bonus to hit and their target a penalty to AC, I think Disseminating Study is logical, cinematic, and balanced. There’s not much to it but it’s honestly one of my favourite Keyword Design options thus far.

So what happened to the blood element I promised for this article? One, it was a massive undertaking. Yes, it’s been a month since I last wrote a Keyword Design, but the reason for the hiatus was to get PaizoCon coverage done before GenCon (I did it!). I could have conceivably written a whole new kineticst element if it was coming together, but there was a pretty big thematic issue. “Blood” is a concept that I think works as an element esoterically, but leech has a very specific connection to blood (pun not intended, I’m seriously, but wow what an unintended pun!) and it wasn’t broad enough that the sanguikineticist fit the keyword.

I’ve saved the work elsewhere and if it fits another keyword, I’ll plug it in there. That’s not me fishing for a broad blood keyword, BTW, just a fact.

Thanks again to Nick V for the keyword suggestion. If you have thoughts on the balance and use of these abilities, or you would like to offer a single word that you think can inspire a mundane item, a magic item, a feat, a spell, and a class option, let me know in the comments below.