This is a game of Vampire the Masquerade, set primarily in the modern nights using the VtM Revised rules for most things, though I intend to migrate to VtM v20 during the course of play. There are a few house rules that I have imposed / agreed / conceded. Here I will collect them so we have a reference to refer back to.

The story we are telling is the tale of NYC, so the first rule is that the players need to be involved in the city. The characters we have are great examples of NYC residents and all have moved to Manhattan to allow us to focus the tale around the Camarilla.

The thing every player wants to know most between games. These are common to all of the World of Darkness beings.
CR x4 . . . . . . . . . Attribute
CR x2 . . . . . . . . . Ability
. . 3 . . . . . . . . . . . New Ability
In-game action. . .Background
CR x1 . . . . . . . . . Willpower (CR x2 for non-vampires)
Freebie cost . . . . Flaw or Merit, plus good in-game reason

These are those things unique to vampires.
CR x5 . . . . . . . . . Clan Discipline *
CR x6 . . . . . . . . . Special rule for Caitiff and Pander Disciplines *
CR x7 . . . . . . . . . Out of Clan Discipline *
. . 10 . . . . . . . . . . New Discipline (even if its in clan)
CR x4 . . . . . . . . . Path (Thaumaturgy, Necromancy, etc)
. . 7 . . . . . . . . . . . New Path (Thaumaturgy, Necromancy, etc)
CR x2 . . . . . . . . . Virtue (does not increase derived stats)
CR x2 . . . . . . . . . Path of Enlightenment, Humanity or Road

*
Either significant time or training is required to increase
There is a restriction of 3 dots as a maximum for low Blood Power kindred (3 or less, 9 years old or less, for NPCs this is increased to 4)
Kindred are assumed to have been trained in the first 3 dots of their initial 3 selected disciplines (or 4 if the extra clan discipline merit was taken)
Training is provided up to the limits of the knowledge of the Mentor, if the Mentor does not know it they can not train
Kindred within a coterie may train each other, however this occupies time that prevent the trainer from doing

The 'generation' background has been replaced with a blood power system, players will age naturally at a slow rate. All NPCs have been modified to fit within this system.

Both NPCs and players may occasionally abuse kindred law and 'diablerise' another kindred to accelerate this ageing. This is a crime of the highest order (unchanged) leaving black bloodvein-like streaks in the diablerists aura for (roughly double the age difference in days). The consumption is a physical (not spiritual) act, and so the only gain is +half the blood potency rating that the victim has above the diablerist (rounding based on age difference). Example, lets take a 10th generation vampire who is blood power 7 and 124 years since their embrace, they diablerise an 9th generation vampire who is blood power 8, and 125 years since the targets embrace. The diablerist has aged naturally to 7.5 blood power. The ST considers the age of the victim compared to their own age, a difference of only 6 months. The ST also considers the difference between 7.5 and the victims 8 blood power. The ST then selects the lower of the two increases, both ammount to blood power 8 but the increase is either half of the 50 year difference between categories or half of the characters age difference. The ST elects to age the diablerist by an unspecified period between 3 months and 25 years. This crime will be visible in the aura for a time that the ST keeps secret, it may be as short as 6 months or as long as 50 years.

Thus it is possible for kindred to consume themselves into oblivion as diablerie will weaken them as a species, losing well earned age from the whole. While the Sabbat appear to support the practice, the other groups all uphold that this is a crime to be punished and never excused. The evidence of this crime is visible as black bloodvein-like streaks through the diablerists aura. The duration of this evidence is a number of years equal to 1 tenth of the victims age in years, though remember a dialerists age increases so diablerising a diablerist you know was embraced a decade ago may not set you in the clear a year later as you might assume.

As per v20, a roll of a 10 results in 1 success only. (previous editions allowed other affects)

As per v20, a roll of a 1 results in a success being deducted. If there are MORE 1's remaining than successes, then the roll is Botched.
House clarification, Damage rolls do NOT suffer this flaw.

If you don't have any dots in the Talent, then roll the Attribute on its own.
If you don't have any dots in a Skill, do the same but the TN is +1.
If you don't have any dots in a knowledge, you can't roll.

Examples
If the roll that is called is Per+Ale(7), and you have no dots in Alertness, roll Per(7) instead.
If the roll that is called is Dex+Dri(7), and you have no dots in Drive, roll Dex(8) instead.
If the roll that is called is Dex+Med(5), and you have no dots in Medicine, you can not roll.

Some abilities are harder or limited depending on you're characters experience, eg. if you have drive 1 and you switch from motorbike, to car then stick shift classic sports car then you might have cheated. But if you're background tells me you're a part time garage mechanic's apprentice and likely to have exposure to this variety that is different

Abilities and Attributes, gain a speciality when the character has 4 dots in them.
If a speciality is applicable to a roll, then any 10 rolled is counted as 2 successes.
House clarification, when you learn Crafts you gain a speciality with the first dot, rather than the fourth
House clarification, damage rolls can not be 'specialised' in

Several disciplines have changed;
Auspex(1) has been swapped with Protean(1). And Protean(1) has copied from the Werewolf Gift of the same name.
Protean(2) and Protean(3) have been swapped.
The Potence, Celerity and Fortitude disciplines have been adjusted slightly. (All previous play groups seemed to prefer the original versions so, by their request, these have been the baseline. Conversely the game authors have downgraded them significantly over the years, these downgrades have been incorporated in part. The authors reasoning was more apparent when we played through a lengthy Werewolf campaign.)
Fortitude reverts to the second edition form (armour works in a very similar way too)

All powers found in all editions have been brought into the game. In some cases this required them to be corrected to align them with their Revised edition variants. To explain, many powers are similar to powers from other disciplines. eg. In general terms, Serpentis shares much in common with Protean, and Animalism and Necromancy share some commonality with Dominate. Thus where a power in the revised edition was corrected by the authors and another similar power was not brought forwards I was able to apply the same upgrade to the power, aligning it with the system as a whole. For some of the very old powers this process was pushed through each edition tier separately.

Another influence to the disciplines has been debates held in previous games over exact nature and wording of the power. Many powers in this game are worded in inexact vague terms, and my play groups have found more precise text that describes the power.

Spend X blood to ... Access a discipline or power that requires blood to be spent as a cost
Spend 1 blood to ... Awaken after the day of forced slumber ends (which is at a varying time depending on humanity/road). This fuels the mind and the body for the duration of the night. It may be possible that some very old kindred are able to skips days, even years by skipping this step without spending blood (voluntary torpor is a misnomer).
Spend 1 blood to ... Increase a Physical Attribute by 1 point, lasts until the end of the scene (or roughly 20 minutes). Maximum the lower of CRx2 or BloodPotency Maximum +1 (ie. 6). Kindred of 400+ years in time spent active, gain +1 to BloodPotency Maximum, then another +1 after 750years, etc
Spend 1 blood to ... Make the heart beat like a human, lasts a scene, the skin is still pallid and cold.
Spend 1 blood to ... Make the skin look and feel like a mortals when touched, lasts a scene, the heart does not beat though. The merit "Blush of Health - 2pt" allows this without spending blood and is permanently active.
Spend 1 blood to ... Simulate the nether regions operating correctly. Be warned though, the only fluid in the kindreds body is blood. Useful for feeding but there is limited feeling and no urge.
Spend 1 blood to ... Operate the stomache. Allows food and drink to be swallowed. The taste of the food is minimal, reduced to basic sweet, savory, oily physical sensations. Lasts a scene, after which time the food and drink must be regurgitated or more blood spent, to keep it down longer. Capacity is far less than a mortal, and over eating to the extreme will cause bashing damage. That damage may voluntarily be accepted without soak, or the material will be immediately evacuated. The merit "Eat Food" replaces this rule, capacity is normal for a mortal, no damage is suffered from over eating, the food tastes as it would for a mortal and the effect while not being exactly permanent allows the regurgitation to be on command at a time when the kindred chooses.
Spend 1 blood to ... Heal 1 point of Bashing Damage. Note that mortals regenerate this type of damage slowly over many hours and days
Spend 1 blood to ... Heal 1 point of Lethal Damage. Note that mortals regenerate this type of damage slowly over many days and weeks
Spend 5 blood and 1 Willpower to ... Heal 1 point of Aggravated Damage. Note that mortals convert Aggravated damage from supernatural claws or magic into Lethal damage

Bashing Damage - being punched, kicked, tripping over, etc
Bruised(-0d) .......... After 1 Hour if they pass Stamina(8)* this box is healed
Hurt(-1d) ............. After 3 Hours if they pass Stamina(8)* this box is healed
Injured(-2d) .......... After 1 Day if they pass Stamina(8)* this box is healed
Wounded(-3d) .......... After 3 Days if they pass Stamina(8)* this box is healed
Mauled(-4d) ........... After 1 Week if they pass Stamina(8)* this box is healed
Crippled(-5d) ......... After 1 Month if they have good medical care and pass Stamina(8) this box is healed
Incapacitated(-All) ... After 1 or more Months if they have good medical care and pass Stamina(8) this box is healed
Note * Mortals automatically succeed if they rest fully for the duration

Lethal and Aggravated Damage - being shot or stabbed, falling off buildings, etc
Bruised(-0d) .......... After 1 Day if they pass Stamina(8)* this box is healed
Hurt(-1d) ............. After 3 Days if they pass Stamina(8)* this box is healed
Injured(-2d) .......... After 1 Week if they pass Stamina(8)* this box is healed
Wounded(-3d) .......... After 1 Month if they pass Stamina(8)* this box is healed
Mauled(-4d) ........... After 3 Months if they pass Stamina(8)* this box is healed
Crippled(-5d) ......... After 3 Months if they have good medical care and pass Stamina(8) this box is healed, and the mortal permanently loses -1 to a physical attribute (which can be replenished by spending XP but only if they have good medical reasons for doing so)
Incapacitated(-All) ... Without immediate emergency medical care they will die. After Many Months if they have good continuous medical care and pass Stamina(8) this box is healed, if the roll fails they die.
Note * Mortals automatically succeed if they rest fully for the duration
Note Vampires that are incapacitated due to Lethal damage do not die, they are torpored for several weeks depending on their humanity. If left in the open they will burn up in the morning sun.
Note Vampires that are incapacitated due to Aggravated damage do not die, but may not act other than to heal with 5 blood and 1 willpower per wound (if a vampire awakens with aggravated damage from a previous night, the first point may be healed without spending willpower)

Blood Loss from being fed upon
1 Blood Taken ......... If the victim has no Lethal damage, set the wound track to Bruised (lethal)
2 Blood Taken ......... If the victim has no Lethal damage, set the wound track to Hurt (lethal)
3 Blood Taken ......... If the victim has no Lethal damage, set the wound track to Injured (lethal)
4 Blood Taken ......... If the victim has no Lethal damage, set the wound track to Wounded (lethal) and if they do not recieve emergency medical care within the hour they must pass a Stamina(8) check or die
5 Blood Taken ......... If the victim has no Lethal damage, set the wound track to Mauled (lethal) and if they do not recieve emergency medical care in the next few minutes they must pass a Stamina(8) check with 3 successes or die
6+ Blood Taken ........ They die

Officially these are the rules -

Stamina(8) to soak, a botch increases the damage. 5' is 1 Lethal, 10' is 2, increasing 1Dmg every 10' thereafter up to a maximum of 10Dmg.
House rules
........... The maximum is 12Dmg at 110' (falling 10'/s for 12 seconds up to terminal velocity)
........... Due to the Fortitude revert this makes the '(movie)underworld drop' possible