Modded Maze Rats

I've been out of DMing for several months now, but had some bored friends on Monday and it was decided to do some dungeon crawling. I've had the framework of a custom ruleset building itself in my head for almost a year and felt ready to do some playtesting, so I bolted the important bits onto a Maze Rats chassis and rolled out with the Tomb of the Serpent Kings. Play reports will be progressively added below the rules (more for my reference than for general enjoyment, haha).

Rules as Maze Rats, except:

Dice, Skills:

• Uses a different dice mechanic that I'm testing for a future system. Stat value, from 1-5, dictates base number of dice a player rolls for actions using that stats, looking for dice to come up as "successes." (Most tasks require 1 success, but some tasks require more, and extra successes may boost the speed, safety, or efficacy of the task.) Characters usually roll with 2-in-6 for success (a result of "1" or "2" counts that die as a success), while proficiency raises this to 3-in-6 and mastery to 4-in-6. Bonus or penalty dice may apply, but rarely more than +/-1.
• No attack value; roll with stats. (Many characters will end up proficient in some kind of weapon.) Number of successes (hereafter: #s) are compared with monsters' dodge scores (usually 0-2) to calculate a hit. Damage is:
• 1 damage for unarmed attacks
• #s for improvised weapons
• #s+1 for light weapons and ranged weapons
• #s+2 for heavy (two-handed) weapons

Stats:

• Health equals Str+Lvl
• No Attack stat (see above)

Hazard Die:

• When in dungeon:
1. Light depletion (torches burn out, lanterns use one out of six portions of oil)
2. Hunger (characters must eat a ration or gain a point of exhaustion; a great opportunity for a one-hour rest, below under Rest and Recovery)
3. Thirst (characters must drink water - a waterskin holds three uses - or suffer as Hunger)
4. Mishap (save or break a fragile item, suffer a fall, make a loud noise, or there is a disadvantageous environmental change like flooding or quakes)
5. Trace (signs of an encounter that could be pursued or avoided; the next roll of 6, below, will reveal this monster unless measures are taken)
6. Encounter (roll off your favorite encounter or wandering monster table!)
• When in wilderness:
1. Weather change (bad weather may cause poor visibility, food spoilage, exhaustion...)
2. Hunger (as above)
3. Thirst (as above)
4. Mishap (save or become lost, suffer a fall, lose an item...)
5. Trace (as above)
6. Encounter (as above)
• When in town:
• No hazards, at least for the current campaign. Waterskins replenish, and lifestyle costs may need to be paid (see below, under Rest and Recovery).

Wounds/Exhaustion/Stress

• Combat and dungeon hazards often incur harm:
• Each point of Exhaustion incurs a one-die penalty for all physical checks. If built up to a character's Strength value, that character will gain a (possibly) permanent physical disease or disability (asthma, fever, cancer...) when they next sleep.
• Each point of Stress incurs a one-die penalty for all mental checks. If built up to a character's Will value, that character will gain a (possibly) permanent mental disease or disability (depression, paranoia, psychosis...) when they next sleep.
• Wounds occur when a character has taken total damage exceeding half their health; a random body part (1d6: 1-head, 2-chest, 3-L-arm, 4-R-arm, 5-L-leg, 6-R-leg) becomes wounded, incurring a one-die penalty for all actions using that body part.
• Body parts become crippled when a character is reduced to 0hp, or takes damage while at 0hp. That body part becomes unusable; depending on the nature of the damage, a crippling wound to the head or chest will often result in death.

Rest and Recovery

• A one-hour rest (a break), with food and water, removes one point each of exhaustion and stress per character. (Roll a hazard die if this rest was not prompted by hunger or thirst on the hazard die, above). 
• A ten-hour rest (making camp), with food and water, removes one point each of exhaustion, stress, and damage per character. The party must make camp each two wilderness turns or fifty dungeon turns (or combination thereof) or suffer a point of exhaustion and stress. The party may not make camp more frequently than one wilderness turn or twenty-five dungeon turns.
• A full day of rest in town removes all exhaustion, stress, and damage, and costs one silver per character.
• A full week of rest in town removes all of the above and heals one wound, costing ten silver per character.
• A full month of rest in town, with skilled medical care, heals a crippled body part (though usually a permanent loss of one point of an appropriate stat occurs), and costs one hundred silver (doctors are expensive!). Non-crippled characters merely pay ten silver per week, and can usually find a job to offset such expenses.

Equipment

• Silver standard!
• Prices:
• 1sp for simple items and most bundled consumables on the Maze Rats item list (rations x3, waterskin, torch x3, bedroll...)
• 3sp for most other non-combat items (bear trap, lantern, shovel...)
• 5sp for shields
• 10sp for most weapons
• 20sp for light armor
• 40sp for heavy armor

Character Creation:

• Start at level 1.
• Roll a profession (I used Ten Foot Polemic's 200-item list, but the Maze Rats table - item 8 on the Character Creation page - is just fine). Characters are proficient (see above, under Dice) with anything related to their profession.
• Gain weapon and item as per the profession list above, then roll five more items off the Maze Rats equipment table.
• Again, with default Maze Rats backgrounds, just roll six items instead.
• Choose one of the following for combat gear:
• A light weapon
• A heavy weapon
• A ranged weapon
• Light armor
• A shield
• You have 3d6 silver. Spend on any further equipment (above).
• Choose one extra thing you are proficient at (or, gain a spell slot).
• Choose or roll for a cosmetic detail or two; default Maze Rats tables are fine.
• Name your character. 

Levelling Up:

• At the end of each session, each character may become proficient (see above, under Dice) at one thing they did that session, like using a certain weapon, sneaking, lifting... or may gain an extra spell slot.
• One person is also chosen to level up their character. You can work out a fair method, but I use The Hat:
• First session of a campaign: place each player's name in a hat.
• End of each session:
1. Check if any new players have joined the campaign since the hat was filled. If so, add their name(s) to the hat.
2. Draw a name. If at the table, this person levels their character (below). If not at the table (skipped/missed this session/no longer playing), keep drawing. Do not replace drawn names.
3. When the hat is empty, start again, as if it were the first session of the campaign.
• Leveled characters gain one health (remember, health = Str+Lvl) and may choose to attempt to increase one stat by rolling a d6. If the result is above the value of the chosen stat, that stat increases by one point.

Session 1 - 11/20/17
Characters:
Quillis, sinecure
Mestis, sinecure
Happenings (spoilers!):
Rolled up starting characters.
Little exposition: just plopped the players up an uninhabited vale several hours from town, told them their paperwork had turned up an ancient map, and that, as minor bureaucrats of the Church, the pagan tomb noted on the map needed to be verified so the map could be filed away if it was accurate.
Cracked the tomb, players slowly and cautiously explored the four coffin rooms, avoiding cracking the sarcophagi but triggering three hazard rolls (rainstorm threatening flash flooding into the now-open tomb, distraught moose outside and unable to enter due to antlers, and an agitated venomous snake washed into the tomb by the rain.
Open the coffins, didn't crack the clay shells until the sorcerer's coffin was opened and the cursed ring revealed. Quillis was very cautious and moved on, Mestis got greedy and pulled the ring off, getting a full dose of gas (incurring one point of damage and one point of exhaustion under my system).
Remaining clay shells cracked from a range with a hefty rock fragment, amulets looted.
Quillis' careful search for trapdoors revealed the hammer trap. Bar carefully removed without triggering trap, Mestis stood ready to trigger trap as Quillis opens the door.
Skeletons (awakened by earlier encounter roll) grab Quillis' wrist; Quillis sacrifices the amulet from his wrist to get free, then signals Mestis, who releases the hammer as Quillis throws the door wide. Three skellies wasted.
Bones sealed into coffin, hammer trap reset, with a tensioned rope across the doorway ready to trigger it (if escaping, the players reasoned, they could slide under the rope and cut it to waste whatever might pursue them).
Rainwater entering the tomb was discovered to drain under the snake-god statue. Party resolved to temporarily seal the tomb, return to town, inform the bishop that the tomb needed cleansing, and acquire more goods and equipment for a second venture to line their pockets with artifacts.
Snake ring "bit" Mestis the next morning. He persists in keeping it on.
Bishop didn't want to waste resources on a sealed tomb, but was persuaded after being given 5sp from "the sale of pagan grave goods." Authorized a return, next time [hopefully] with aid.
Quillis leveled up, now having five hitpoints (Str3+Lvl2) and proficiency in searching for things.
Reflections:
Maze Rats is a great chassis.
Limited backpack space is a bummer. (But a good rule.)
My first time using hazard dice went well.
Crowbars are great.
I'm used to 5E, where it's comparatively uncommon NOT to have darkvision. That is bad. Limited lighting and encumbrance is kind of a needed rule.
First time playing an actual module! (Because I wasn't planning on this session and needed something quick, haha.) Tomb of the Serpent Kings 3.0 has treated me well; I've been able to parse it quickly and effectively. The first level of the dungeon was a perfect size for one session, as advertised.
Players liked the consistent themes so far, and puzzling with the door hammer.

Session 2 - 11/23/17
Characters:
Quillis, sinecure
Mestis, sinecure
Friga, weaver
Tubal-Cain, outlaw
Happenings (spoilers!):
The bishop, having pulled some strings to gain two extra helpers, sent the party back to the Tomb of the Serpent Kings. The short journey to the tomb was accomplished quickly and without incident ["traces" of moose rolled on the hazard die].
Carefully rolling the ominous snake-god statue aside, the party descended into the lower tomb and found a hallway with six serpent-man statues - one, misaligned. Taking note of this, the party discovered an octagonal atrium with six more doors and an open passage leading off, and bad oily water in a pool in the center.
Returning to the misaligned statue in the hallway, they discovered it to move aside and reveal a secret guardroom with a valuable silver icon [20sp] and two functional polearms.
These taken, the sinecures used their quasi-magical wax seals to ward the doors in the atrium, and explored the last passage, which led to a room of clay snake-men (with no loot within). The sound of smashing ceramic awakened two mummy fragments in the oily pool, who stirred and prepared to strike. The Friga and Tubal-Cain noticed this and struck preemptively with a polearm, only to be surprised when it returned from the pool with a hand gripping the polearm's head!
A quick quarrel from Mestis' crossbow sent it back to the pool, dead, while a second hand crawled forth and scratched ineffectually at Tubal-Cain's leather armor, who brutally smashed it with his shield and kicked the fragments back into the pool.
Reasoning that if there is a burial in the pool, there might be burial goods too, the party made use of a fishing net Friga luckily had to trawl the gross waters and pull up 1) a heavy golden chain [35sp], 2) an astrolabe [20sp], and 3) a insane and very angry mummy head making quite the racket. Tubal-Cain smashed it too, out of frustration [but the sealed doors all around prevented any wandering monster checks at the noise].
The party decided to explore the doors in clockwise fashion. Quillis and Mestis removed their seal on the first door to the left from the entrance hallway and slid the stone slab open. Unfortunately, thick dust had covered an electrum plate on the ground, and Quillis' tread triggered it, sending a powerful lightning bolt shooting down the cramped hallway! Quillis and Mestis both fared badly, but Mestis weaker constitution [3hp] failed him and his heart stopped [3 damage inflicted a crippling wound in the torso location as determined by a d6 roll]. The party, discouraged, assembled a quick net-and-polearm litter and bore Mestis out of the deadly tomb, resolving to return with reinforcements.
The bishop approved much of this plan, given the gift of the valuable silver icon from the hidden guardroom.
Reflections:
I feel a little unhappy with my ruling regarding the lightning trap. Electrum shines, and the party had light, but I reasoned the plate would be covered with dust as the rest of the dungeon and wouldn't be visible without a search (which wasn't attempted). Still, perhaps a will roll for the leader (Quillis) to spot the sparkle of danger would've been reasonable. I granted a dexterity roll upon stepping on the plate (to avoid putting full weight on it), but that was failed. Still debating, too, how to translate 4d6 lighting damage into modded Maze Rats - I just did 4 damage (with resistance rolls under strength to reduce it), but perhaps I should've done 2 damage and 2 stress, or 4 damage and 4 stress (which would've given Quillis a mental illness, while also killing Mestis!). I'll have to pay closer attention to translating the damage Tomb of the Serpent Kings dishes out to the very low health modded Maze Rats characters have, and taking opportunities to incorporate stress and exhaustion.
It was a very pleasant post-thanksgiving game. Quillis, Friga, and Tubal-Cain were all played by persons unfamiliar to D&D, and I very much appreciated the down-to-earth approach the immediately took when introduced to Maze Rats - playing it like life(-and-death), rather than a power fantasy (as I've seen too many people starting in late D&D editions to embrace).