Resources

Thinking about starting a West Marches? Read Ben Robbins first. Ben ran the original for a little over two years and wrote it up in five blog posts, and plenty of the guides and videos below point back to them.

The rest is what I'd send a GM who asked where to look next. Our own Running West Marches guide boils Ben's posts and the Mystic Arts video down to one page.

Start with Ben Robbins

The posts are short. If you only have time for two, read the first and the last.

Grand Experiments: West MarchesWhere it started. No set time, no set party, no plot, and players booked their own sessions by email.
Part 2: Sharing InfoPlayers writing up their own sessions, and the shared map the characters carved into a tavern table.
Part 3: RecyclingReusing your prep, like moving new residents into a cleared dungeon, and a wandering monster table for each region.
Part 4: Death & DangerDice rolled in the open, and danger that rises the farther you get from town.
West Marches: Running Your OwnTips for running your own, ending on the biggest warning of all: "Fear the social monster."

Written guides

Starting a West Marches Campaign, Step By Step · Roleplaying TipsSix parts of prep, written for GURPS, and most of it works in any system.
Planning a West Marches Campaign in D&D 5e · DungeonSolversA 5e game that levels on milestones (I'd use XP). The best tip is to write quests last, once the players have said where they want to go.
Hexcrawl · The AlexandrianJustin Alexander's 13-part hexcrawl series. It isn't about West Marches, but it covers the map half of one.
What Is A West Marches Campaign? · CzepekuA short intro from a battlemap maker, and the one to send a player who's never heard the term.

Building an Online TTRPG Toolkit (Stephen Collins)

A GM with a new online group wrote up the tools they settled on. Part 4 reviews this site, wish list included.

Part 1: Campaign Record-Keeping and DevelopmentCampaign notes and homebrew in Obsidian, with plugins for everything from dice rolls to initiative.
Part 2: Group CommunicationThe group's Discord server channel by channel, and its three bots (ours is one). Read it before you set up your own.
Part 3: Online Character Sheets, Tabletop Visualisation, and Content SharingWhy the group went with D&D Beyond and its Maps VTT, and what Maps still can't do.
Part 4: Campaign Management, Scheduling, Economy, and Notes (and a Review)Setting up a community here for a group of five, from the creation wizard to the marketplace.
Part 5: Sound and FuryMusic and ambience for online sessions, played into Discord with Pocket Bard and Kenku FM.

Rules for the system guides

The Shadowdark RPG and Pathfinder 2e guides take their numbers from these.

Shadowdark RPG Quickstart Set · The Arcane LibraryThe free quickstart, with the treasure and leveling rules.
Delving Into Shadowdark · Sly FlourishMichael E. Shea on running Shadowdark RPG, from real-time torches to how many characters die.
GM Core: Rewards · Archives of NethysPaizo's rules for Pathfinder 2e XP and treasure, free online.

Rather watch?

The West Marches | Running the Game · Matthew Colville · 31 minColville hadn't run one yet in 2017, but explains Ben's game clearly.
Critical Role isn't actually doing West Marches, but you can! · Mystic Arts · 26 minDon't mind the title. It's how to run your own, from someone who ran nearly 100 sessions for about 50 players.
How To Run A West Marches Campaign · The Arcane Library · 1 hr 17 minA live stream, so it wanders, but the parts on overland travel between sessions and tying game time to real time are good.
How to Build A West Marches Campaign (Step by Step Tutorial) · Enter the Dungeon · 1 hr 54 minA campaign built on camera up to session 0, with a session 0 template linked under the video.
Make hexmaps easily with THE POWER OF OUTLINES! · Mystic Arts · 19 minDrawing a hex map one layer at a time, terrain first and landmarks last.
Why 3-mile hexes make HEXCRAWLS fun · Mystic Arts · 16 minThe horizon is about three miles away, so players can see into the next hex before they pick a direction.

Resources

The rest is what I'd send a GM who asked where to look next. Our own Running West Marches guide boils Ben's posts and the Mystic Arts video down to one page.

Start with Ben Robbins

The posts are short. If you only have time for two, read the first and the last.

Grand Experiments: West MarchesWhere it started. No set time, no set party, no plot, and players booked their own sessions by email.

Part 2: Sharing InfoPlayers writing up their own sessions, and the shared map the characters carved into a tavern table.

Part 3: RecyclingReusing your prep, like moving new residents into a cleared dungeon, and a wandering monster table for each region.

Part 4: Death & DangerDice rolled in the open, and danger that rises the farther you get from town.

West Marches: Running Your OwnTips for running your own, ending on the biggest warning of all: "Fear the social monster."

Written guides

Starting a West Marches Campaign, Step By Step · Roleplaying TipsSix parts of prep, written for GURPS, and most of it works in any system.

Planning a West Marches Campaign in D&D 5e · DungeonSolversA 5e game that levels on milestones (I'd use XP). The best tip is to write quests last, once the players have said where they want to go.

Hexcrawl · The AlexandrianJustin Alexander's 13-part hexcrawl series. It isn't about West Marches, but it covers the map half of one.

What Is A West Marches Campaign? · CzepekuA short intro from a battlemap maker, and the one to send a player who's never heard the term.

Building an Online TTRPG Toolkit (Stephen Collins)

A GM with a new online group wrote up the tools they settled on. Part 4 reviews this site, wish list included.

Part 1: Campaign Record-Keeping and DevelopmentCampaign notes and homebrew in Obsidian, with plugins for everything from dice rolls to initiative.

Part 2: Group CommunicationThe group's Discord server channel by channel, and its three bots (ours is one). Read it before you set up your own.

Part 3: Online Character Sheets, Tabletop Visualisation, and Content SharingWhy the group went with D&D Beyond and its Maps VTT, and what Maps still can't do.

Part 4: Campaign Management, Scheduling, Economy, and Notes (and a Review)Setting up a community here for a group of five, from the creation wizard to the marketplace.

Part 5: Sound and FuryMusic and ambience for online sessions, played into Discord with Pocket Bard and Kenku FM.

Rules for the system guides

The Shadowdark RPG and Pathfinder 2e guides take their numbers from these.

Shadowdark RPG Quickstart Set · The Arcane LibraryThe free quickstart, with the treasure and leveling rules.

Delving Into Shadowdark · Sly FlourishMichael E. Shea on running Shadowdark RPG, from real-time torches to how many characters die.

GM Core: Rewards · Archives of NethysPaizo's rules for Pathfinder 2e XP and treasure, free online.

Rather watch?

The West Marches | Running the Game · Matthew Colville · 31 minColville hadn't run one yet in 2017, but explains Ben's game clearly.

Critical Role isn't actually doing West Marches, but you can! · Mystic Arts · 26 minDon't mind the title. It's how to run your own, from someone who ran nearly 100 sessions for about 50 players.

How To Run A West Marches Campaign · The Arcane Library · 1 hr 17 minA live stream, so it wanders, but the parts on overland travel between sessions and tying game time to real time are good.

How to Build A West Marches Campaign (Step by Step Tutorial) · Enter the Dungeon · 1 hr 54 minA campaign built on camera up to session 0, with a session 0 template linked under the video.

Make hexmaps easily with THE POWER OF OUTLINES! · Mystic Arts · 19 minDrawing a hex map one layer at a time, terrain first and landmarks last.

Why 3-mile hexes make HEXCRAWLS fun · Mystic Arts · 16 minThe horizon is about three miles away, so players can see into the next hex before they pick a direction.