Beyond the Last War

Game System

This campaign uses the Pathfinder 2E Remaster (PF2e) rule system. The Eberron setting is owned by Wizards of the Coast (WotC) with no official published content for PF2e. Consequently, this campaign uses a fusion of content from prior D&D versions back to the first publication for D&D version 3.0.
The "home brew" rules for this campaign are listed below.

Ancestries

The creation of a new player character (PC) includes the random generation of their place of origin and ancestry. This may result in a number of unusual ancestries. If you do not want to play the randomly generated ancestry you have the option to select from the common ancestry in Eberron: Dwarf, Elf, Gnome, Half-elf (Aiuvarin), Halfling, Half-orc (Dromaar), Human, or Warforged.
In PF2e each ancestry also has a heritage, so if you decide on playing a common ancestry you will also need to select a heritage for your character. Note that in PF2e "half-elves" have the Human ancestry with the Aiuvarin heritage, and "half-orcs" have the Human ancestry with the Dromaar heritage.
For flavour the character vital statistics of height and weight will be generated randomly, along with the character birth date on the Calendar of Galifar.

Backgrounds

Each character background will be generated using the optional Deep Background rules outlined in the 2E Gamemastery Guide. This will require making some choices for the PC that add lore and skill feat options.

Classes

You may play any class listed in the Pathfinder Player Core and Player Core 2 Remaster source books.
Additionally, the Inventor class from the Guns and Gears Remaster source book is available as a player character.

Languages

In Eberron there are some unique languages and many of the default Golarion languages from the core rules do not exist. All the languages have been adjusted in Foundry VTT as homebrew elements and also include the new core rule versions of the language names.

House Rules

The items below are modifications to the official game rules used in this campaign.

Class Level

Each PC joining the party will start with 0 XP at the current level of the lowest level PC in the party. Due to the nature of rewards in the game, a party facing appropriate challenges for their level will result in all members converging to the same level over time.

Critical Damage Rule

In this campaign when doubling damage from a critical hit you roll the dice twice and double the modifiers, bonuses, and penalties instead of doubling the entire result. Benefits you gain specifically from a critical hit, like the extra damage die from the fatal weapon trait, aren't doubled.

Critical Hit & Fumbles

This campaign will use the critical hit and fumble cards. This applies to all monsters, including critical hits even if the creature or hazard's level is less than the target's level. Note that Foundry VTT handles the card-draw automatically but only reveals it to the GM.
This is a summary of the critical success or failure results for combat:

Critical Hit Special Rules

Whenever a PC or foe scores a critical hit due to a natural 20 on the die roll, they draw a result from the critical hit card deck and the GM applies the effect appropriate to that attack's type (bludgeoning, piercing, or slashing in the case of a weapon or unarmed attack, or bomb or spell for either a bomb or spell attack roll).
The following special rules apply to critical hit card effects:

Critical Fumble Special Rules

Whenever a PC or foe gets a critical failure on an attack roll due to a natural 1 on the die roll, they draw a result from the critical failure deck and the GM applies the effect appropriate to the attack's type (melee weapon, ranged attack, unarmed attack, or spell).
The following special rules apply to critical failure card effects:

Surprise Round (Clarification)

In the rules as written (RAW) there is no surprise round in combat. The rules rely on more complex rules around stealth, avoiding notice and perception. However, these rules can be complicated and difficult to understand so this is a clarification rather than a house rule change.
It is worth reading over the rules on Perception and Detection, particularly the sub-section on Detecting Creatures. In short, there is no full surprise round in which one side can act while the other side cannot. However, common sense does apply - if one side is caught off-guard they may need to stand, draw a weapon, etc.
Here is an outline of the basic principles:

Getting Tricky

In the above example there are ways to coordinate the attack more effectively under the current rules.
For example, the party decide that their lead fighter is going to open the door then charge and attack the first opponent they see. All the other PCs want to take an action when he does this.
There are a couple of ways this can happen:

Hero Points

Each PC gets 1 Hero Point at the start of each session, but only if the player is present.
Hero points are only awarded during a game session when a character has a particularly heroic moment, at the GMs discretion.
Non-Player Characters (NPCs) never get hero points.
You can spend your Hero Points in one of two ways. Neither of these is an action, and you can spend Hero Points even if you aren't able to act. You can spend a Hero Point on behalf of your familiar or animal companion.

Low Magic

In Eberron magic is wide, not high. In other words, low-level magic is common, with many devices being powered by it. High-level magic is quite rare.
Spells up to 3rd rank have the standard rarity. The rarity of 4th-5th rank spells increases by one step (i.e. common spells become uncommon, uncommon spells become rare, and rare spells remain rare). The rarity of all common and uncommon spells of 6th rank and higher are rare. This is a general rule-of-thumb and could be modified by the GM.

Uncommon Spells

The Game Master (GM) controls the availability of uncommon spells. Player Characters (PCs) typically will not have any uncommon spells at the start of their career or granted to them when advancing a level. They will need to learn/acquire them during play.

Rare Spells

The GM controls the availability of rare spells. PCs will not have any rare spells at the start of their career and will have to acquire them during play.

Slow Advancement

This campaign will use slow advancement where a character levels up after gaining 1,200 experience points (XP) instead of the default 1,000. This will reflect a grittier world focused on lower-level beings.

Awarding Experience Points

In this campaign the party is a team, but experience points (XP) are only awarded to those who participate in the activity generating the reward. If a character does not participate but is a passive observer they may be awarded partial XP at the discretion of the GM.
To use an example from the core rulebook, if the party wins a battle worth 100 XP but the party rogue was off stealing treasure during the battle, the rogue would not earn the 100 XP. Similarly, if the rogue earned XP during the battle by defeating traps to steal some treasure, the rest of the party would not gain those XP.
In those instances, the party level is calculated for all those who participated in the event earning the reward (see Adjusting Encounters).

Proficiency Without Level

In this campaign the rule variant known as Proficiency Without Level (PWL) is being used.
Rules on how PWL is applied in this campaign is described in a more detail here.

Buying and Selling Items

After an adventure yields a windfall, the characters might have a number of items they want to sell. Likewise, when they're flush with currency, they might want to stock up on gear. It usually takes 1 day of downtime to sell off a few goods or shop around to buy a couple items. It can take longer to sell off a large number of goods, expensive items, or items that aren't in high demand.
If they want to sell or buy items, PCs must be in a location where the markets can support that. They can usually sell a single item for half its Price, but the Price for something already plentiful on the market could drop lower, typically to 25% or 10%, or be refused entirely if there's a glut. Buying an item usually costs the full Price; buying higher-level items (or uncommon items if they're available at all) requires seeking out a special vendor or NPC and can take extra time, as detailed below:

Calendar of Galifar

The Calendar of Galifar is the primary calendar system used on the continent of Khorvaire. The calendar divides the year into 12 months, each of which contain 4 weeks and 28 days. Each month corresponds with one of Eberron's moons. Each day is 24 hours long.
The years are counted from the founding of the kingdom of Galifar by Galifar ir'Wynarn I, using the abreviation YK, which stands for "years of the kingdom".
This campaign begins over 20 years after the great war, on Sypheros 27, 1022.

Time Zones - Basic Geography

The world of Eberron is roughly 2/3rds the size of Earth with an axial tilt and rotation that experiences four seasons similar to our Earth. The Prime Meridian (0 degrees longitude) goes through the city of Thronehold, which lies roughly in the centre of the continent of Khorvaire.
Every 15 degrees East or West of that line marks the location of a time zone that is +/- 1 hour (positive going East and negative going West). The table below gives a rough guideline of distance between lines of longitude on Khorvaire. Most locations on the continent will lie somewhere between 15° - 50° North latitude.
If your latitude is ϕ, and you travel 1° of longitude either due West or due East, then you have traveled:
p = 40 cos(ϕ) nautical miles (nm)
The conversion is: 1 nautical mile ~ 1.15078 miles. Note: the COS formula in Excel expects radians as input. To convert to degrees multiply by PI()/180 (for example, COS(20*PI()/180).

Latitude nm (1°) km (1°) miles (1°) miles (15°)
40.0 74.1 46.0 690.5
39.8 73.8 45.9 687.8
10° 39.4 73.0 45.3 680.0
15° 38.6 71.6 44.5 666.9
20° 37.6 69.6 43.3 648.8
25° 36.3 67.1 41.7 625.8
30° 34.6 64.2 39.9 598.0
35° 32.8 60.7 37.7 565.6
40° 30.6 56.7 35.3 528.9
45° 28.3 52.4 32.5 488.2
50° 25.7 47.6 29.6 443.8
55° 22.9 42.5 26.4 396.0
60° 20.0 37.0 23.0 345.2
65° 16.9 19.5 19.2 291.8

Settlements

In the Pathfinder RPG, a settlement's level is used primarily to determine potential jobs on offer for the Earn Income activity, and to determine what level of items are commonly available for sale in that community.
The level of a settlement is also used to determine what items the party might be able to find when looking for magic items available to purchase. This campaign uses the general guidelines from the Kingmaker system. I am expanding slightly on those rules by borrowing some details from the Dungeons & Dragons version 3.5 rules for settlements - notably the rules on gold piece (GP) limit and ready cash.
GP Limit: The gold piece limit is an indicator of the price of the most expensive item available in that community. Nothing that costs more than this limit will be available for purchase in that community. Exceptions may exist with randomly generated items.

Settlement Population Level GP Limit
Thorp 20-80 1 4 gp
Hamlet 81-400 1 10 gp
Village 401-900 2 20 gp
Small Town 901-2,000 3 80 gp
Large Town 2,001-5,000 4-5 300 gp
Small City 5,001-12,000 6-7 1,500 gp
Large City 12,001-25,000 8-9 4,000 gp
Metropolis 25,001+ 10+ 10,000 gp

Ready Cash

Ready Cash represents the amount of money available for immediate use within a settlement. The formula to calculate ready cash is:
Ready Cash = (Population x GP Limit) / 20.
For example, if a settlement has a population of 10,000 and a GP Limit of 1,500 gp the ready cash would be calculated as: Ready Cash = (10,000 x 1,500) / 20 = 750,000 gp.
The ready cash reserves in a settlement will be replenished by 20% every week.