25 Years had passed... The Keep changed... The Caves renewed... A pair of adventurers seek to continue their mother's legacy...
Marking 5 years since starting solo rpgs with Keep on the Borderlands and D&D Basic, tackling Return to the Keep on the Borderlands with Old School Essentials (OSE).
OSE solo - intro | start | partway | end | all season 4 | all dungeon solo
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Adventure Intro - Return to the Keep on the Borderlands
module | ose intro | solo tools | chars | chargen
Keep on the Borderlands was my first solo experience along with the D&D Basic system it was boxed with.
That was 5 years ago, when my group of adventurers got savaged (twice) but one survived both, and Marge Greenfingers lead my initial forays through the Caves of Chaos and around via Basic D&D, Knave 1e, Warlock and other systems.
To mark 5 Years and in keeping with Season 4 - Dungeons, I'm going back to the Caves of Chaos with Return to the Keep on the Borderlands and Old School Essentials (introduced below). Further tying this actual play back to the 1st, I'll be including two children of Marge, raised by their retired from adventuring mother on tales of her adventures...
Return to the Keep on the Borderlands was released in 1999 for Advanced Dungeons and Dragons 2e, in that strange time when a faltering TSR had been taken over by Wizards of the Coast but before D&D 3E came out (in Aug 2020). It had more content, with 64 pages to the 32 in the original.
It features a Borderlands Keep set 20 years (25 years in my version) in the future after the original Keep on the Borderlands, updated with changed and new NPCs (even giving them names!) and more detail. The Caves of Chaos have also been updated, with more varied groups and situations and slightly more narrative.
While most 2E adventures of the late 90's were heavily narrative and plot base, Return to the Keep on the Borderlands is truer to the original. It has light touches of plot, but emphasises that it's a sandbox and gives advice on running this type of adventure (such as advising on using the optional rule of Treasure for XP in the AD&D 2E DM's Guide).
I've never played (or run) Return to the Keep, so it's all new to me. It wasn't an adventure of interest to me when it came out, having never played (or run) the original at that point. (I was running some 2e, but all home-brewed adventures).
For my module prep to run it solo, I had a brief look through to get an idea of the feel and layout / structure of the module. Luckily I'm also good at forgetting those details I did see!
RPG Introduction - Old School Essentials
module | ose intro | solo tools | chars | chargen
Old School Essentials (OSE) is a restatement of the original D&D Basic & Expert (B/X) rules from 1981. I'm using the Advanced Fantasy version, which uses the B/X rules but adds lots of optional rules, as well as a bevy of classes and races such as the Assassin, Drow, Druid and Illusionist.
OSE is known in RPG circles for it's tight layout and ease of use. It's also popular in solo-rpg games for playing old school modules or newer modules done in an old school style. OSE can also easily cope with running low-level AD&D (1e & 2e) adventures, such as Return to the Keep on the Borderlands. I've used it in my solo Stonehell adventures and it's also the basic engine used for the Dolmenwood setting and rpg (which I've also soloed).
For me personally it has all the bits I liked about fantasy adventures in AD&D 2nd Edition, but without the bits I was happy to leave behind. Bits such as extra complexity, larger numbers (escalating Armour Class, hit points, magic item bonuses), exceptional strength and kits.
OSE has characters using familiar D&D parts such as 6 stats, Character Classes, hit points, Armour Class, increased power as level goes up. Combat is fast and brutal and most adventures are designed for a group of 4-8 characters, possibly with some hirelings and retainers along for the ride.
It has strong procedures for dungeon-crawling, combat rounds, encounters, treasure creation and wilderness travel. Another positive for running solo games.
I'll be using the separate class and race from Advanced OSE (no racial classes), with no restrictions on level or class/race combinations. I'll also (mostly) be sticking to the core OSE rules, not adding things in from Carcass Crawler, the Knock zines or other sources. The optional rules being used will be detailed in part 2.
Solo Tools
module | ose intro | solo tools | chars | chargen
I'll be using Chaos Solo Engine - Basic Fantasy, a simple solo emulator and oracle that I'm familiar with (as I wrote it). I'm still working on the Expanded version, which will add more inspiration tables and variants on the basic tools.
Chaos Solo Engine uses d20s for it's oracle, tools and inspiration tables. Core parts include...
- A d20 Yes/No Oracle table which can trigger Events and can use Boons and Banes for different likelihoods.
- A list of Threads, keeping track of quests, plots, open questions and other items related to the character(s)
- A list of Extras, any entities you want to keep in the story/game such as Non-Player Characters, settlements or factions.
- An Events table which introduces chaos into the game, interrupting play or introducing new elements in a similar way to a Gamemaster in a group tabletop RPG.
- A Test the Scene table that indicates if the expected scene starts as expected, is changed in some way, or interrupted entirely.
- Boons and Banes, extra d20s that can be added to the Yes/No Oracle, Events table and Test the Scene to represent positive or negative modifiers or situations in the game.
- Inspiration Tables, d20 tables such as NPCs, Action & Theme, Descriptor & Focus and Starting Situation, to give ideas and sparks for the game.
There's a simple Chaos Solo Engine - Basic Fantasy generator and tool at ChaosGen.

Introducing the Greenfinger Guild
module | ose intro | solo tools | chars | chargen
Burunild Greenfinger
human f baker, neutral fighter 1, sister of Adwen, cheerful, scruffy, aims to make name as adventurer
STR 13 (+1) DEX 9 (+0) CON 11 (+0) INT 8 (-1) WIS 13 (+1) CHA 14 (+1) HP 8
Abilities - Languages (Common), Leadership (9), Stronghold, XP 0 (+5%)
Equipment - platemail, sword, dagger, shield, spear, backpack, 6 torches, large sack, waterskin, weeks rations, tinderbox, 50 ft rope, inscribed knife, 6 gp
Mauth
dwarf f cooper, neutral cleric 1 of Air, haunted, wears furs, motivated by grief, aims to bury brother's ashes at site of a great deed.
STR 13 (+1) DEX 9 (+0) CON 13 (+1) INT 9 (+0) WIS 11 (+0) CHA 9 (+0) HP 7
Abilities - Detect Construction Tricks, Detect Room Traps 1-2, Divine Magic, Infravision, Languages (Common, Dwarf), Listen 1-2, Resistance +3 (magic, poison), Turn Undead, XP 0
Equipment - platemail, mace, shield, sling + stones, small sack, waterskin, holy symbol, 1 gp
Renalfnoc "Ren"
gnome m jeweller, chaotic thief 1, well-groomed, melodic voice, aims to get a set of ten perfect gems
STR 7 (-1) DEX 13 (+1) CON 13 (+1) INT 10 (+0) WIS 10 (+0) CHA 9 (+0) HP 5
Abilities - Defence Bonus, Detect Construction Tricks, Infravision, Languages (Burrowing Animals, Common, Gnome, Thieves' Cant), Resistance +3 (magic), Thief Skills (Climb 87, Find/remove Traps10, Hear Noise103, Hide in Shadows 10, Move Silent 2o, Open Locks 15, Pick Pockets 20, XP 0 (+5%)
Equipment - leather, dagger, sling + stones, backpack, rope, 2 small sacks, 6 torches, flint and steel, thieves tools, 3 oil flasks, 2 war dogs
Adwen Greenfinger
human f blacksmith, neutral illusionist 1, sister of Burunild, friendly, wears bright colours, aims to keep Burunild alive, scruffy, aims to make name as adventurer
STR 11 (+0) DEX 11 (+0) CON 18 (+0) INT 13 (+1) WIS 7 (-1) CHA 18 (+3) HP 7
Abilities - Arcane Magic (spells 1 x 1st, Languages (Common, Dwarf), Leadership (11), XP 0 (+5%)
Equipment - spellbook (audible illusion, chromatic orb, light/darkness, read magic), staff, 4 daggers, backpack, 5 oil flasks, flint + steel, 6 torches, rope, small hammer, weeks rations, waterskin, 12 iron spikes, 2 war dogs, 47 gp
Cedar Jade
half-elf m fisher and furrier, lawful knight (?), austere attire, rumbling voice, aims to establish family legacy
STR 14 (+1) DEX 7 (-1) CON 9 (+0) INT 14 (+1) WIS 11 (+0) CHA 11 (+0) HP 8
Abilities - Chivalric Code, Combat (no missile), Detect Secret Doors, Horsemanship, Infravision, Languages (Common, Elf, Goblin), Mounted Combat, Srength of Will, XP 0 (+5%)
Equipment - platemail, axe, sword, 2 daggers, backpack, waterskin, weeks food, fishing net, wine x2, 22 gp
Character Generation for Old School Essentials
module | ose intro | solo tools | chars | chargen
Character generation is fairly quick for OSE, and as always quicker if you've played it before.
You generated the 6 attributes with 3d6 in order (I'm using the order as I've played with for many years). Choose a race, choose a class, roll up your gold and buy your equipment. Add details such as name, secondary skill (If used) and you're ready to go.
I use a few house rules for chargen such as option of "Flipping the stats" (8/12/14/6/10/13 could become 13/9/7/15/11/8 if desired), maximum hit points at first level.
I'm using a modified options for humans (giving them +1 Cha, +1 Con and the Leadership ability) and also a slight boost to halfelves (+1 Cha, a second background).
One character, Adwen, had exception stats (an 18 and a 17 which became an 18), which is a likely indicator they will die in the first delve into the Caves of Chaos...
Finishing Up
This should be a grand way to wrap up Season 3 of Rolling Solo.
If you liked this there are Solo RPG Articles at Rand Roll, Generators at Chaos Gen and a monthly random tools Newsletter. Or find us on the Rand Roll Discord or an instagram of Random Tables.