I'm curious about play without a group.

Technically, any RPG can be played solo so long as you have a decent GM emulator book such as Mythic. I would say the more crunchy the game, the more bookkeeping you have to do and the longer things take. Which means less fun. Mid to low crunch games are best for your more freeform games that are trying to emulate traditional RPG sessions.

I've played Call of Cthulhu solo. I used Heinrich's Call of Cthulhu Guide to Character Creation to generate my character. It's a bunch of life path tables similar to Traveller. You can go on some very cool and creepy tangents including whole mini adventures. That then generate plot hooks for your character to pursue. Actual gameplay is done via entries in a handwritten and timestamped journal and the Mythic GM emulator. It's all very simple and works out very well.

Other games I've played that have worked out well solo include:

Black Star
Savage Worlds
Star Wars D6
Lamentations of the Flame Princess(OSE and other B/X OSR games too)
Fabula Ultima
Exalted vs World of Darkness

You also have games like Four Against Darkness or 2d6 Dungeons. These are made specifically to be straight dungeon crawls more reminiscent of Warhammer Quest (considerably cheaper than the modern incarnations of these kinds of board games though) or video games like Wizardry. You don't need to GM them. You just go through dungeons, get loot, level up and repeat. More board game like than really RPG. But still very fun for lazy evenings. You can get the books for under £20 and have a really good time with them. 

Quote from: GiantToenail on September 29, 2023, 07:37:43 AM
I'm curious about play without a group.

Scarlet Heroes i think have been designed specifically for just that scenario.

Scarlet heroes has a good DM emulator that can be plugged into other systems.

I lost interest in Mythic after they started the edition treadmill and some less than strllar attitude last year.

Not an RPG, but a skirmish wargame with RPG elements is 5 Parsecs from Home. It's sister fantasy (D&D) version is 5 Leagues from the Borderlands. Both give a campaign framework for procedurally generating scenarios. Might be useful for a solo RPG.

I did a short Basic D&D solo campaign with 4 characters and running random dungeons from the Dunjon website. Had to do a fair bit of back end work, but as a GM, that was part of the fun.

Quote from: King Tyranno on September 29, 2023, 08:48:43 AM
Technically, any RPG can be played solo so long as you have a decent GM emulator book such as Mythic.

I've been eyeing Mythic, but haven't taken the plunge yet. Have you used it/looked through it? Any opinions?

d100 dungeon is amazing. You can literally run a sandbox campaign with this system.  Not only can you do dungeons but with additional books you can expand outward to randomly generate cities, forts, hex crawl maps, etc.  This is as close to Pen and Paper solo campaigning as it gets.   Very easy to run and play and I've picked up the d100 space series as well.

Four against the darkness is good for a dungeon crawl.

Quote from: Ratman_tf on September 29, 2023, 09:41:26 AM

Quote from: King Tyranno on September 29, 2023, 08:48:43 AM
Technically, any RPG can be played solo so long as you have a decent GM emulator book such as Mythic.

I've been eyeing Mythic, but haven't taken the plunge yet. Have you used it/looked through it? Any opinions?

I used Mythic extensively. All the RPGs I mentioned were played with Mythic. It's very versatile but I found I rarely needed more than the standard Yes/No matrix. You adjust the probabilities of a yes based on the likelihood of a yes occurring. And that answers pretty much any question you would normally have for a GM. I will say for CoC in particular I moved on to The Solo Investigator's Handbook recently. As a GM emulator it's got more specific monster and NPC generators for horror focused games. Mythic is fine for 99% of your solo gaming needs though.

Just to add a bit of clarity, Mythic GME (game master emulator) is different from Mythic the RPG (both by Word Mill.)  If you are on a budget, there are other tools out there as well like CRGE. 
https://www.drivethrurpg.com/product/145426/CRGE-Conjectural-Roleplaying-GM-Emulator

I'm also a big fan of the GMA decks which come in a variety of genres.
https://www.drivethrurpg.com/browse/pub/6395/Larcenous-Designs-LLC

The main advantage of these tools is that can be used with just about any traditional RPG.  So, you're not just limited to purpose built solo games (although there are some good ones out there as well.)

If you like using tarot cards as inspiration and a randomizer, I wrote Four Houses in Chaos.  It's a freebie along with my other solo tools...
https://www.drivethrurpg.com/browse/pub/9792/Tangent-Zero

It's probably something best learned by example. There are a number of examples here: https://www.rpgsolo.com/forum/forum-4.html, or if you prefer video: https://www.youtube.com/@MeMyselfandDieRPG.

As someone mentioned earlier, Mythic has a large number of supplements, and I don't recommend them. The base system is better as-is.

Just for fun, here are a variety of styles and systems that I have used in the past.
https://www.deviantart.com/zircher/gallery/85563109/solo-stories

Of course, if you like rabbit holes and drinking from the fire hose...
https://www.reddit.com/r/SoloActualPlay/

I'm personally not crazy about the system, but The One Ring 2e has a set of solo rules called "Strider Mode" that some people like.  And Swords & Wizardry just released a solo module that's sort of like one of those old "Choose your own adventure" books.  OSE is pretty easy to do solo.

Quote from: GiantToenail on September 29, 2023, 07:37:43 AM
I'm curious about play without a group.

I'm a fan of Mythic. But when it comes right down to it, I find the 1E DMG appendices to be the most useful in running a solo game. A key difference in approaches is the random tables in Mythic are populated with what I'd call the narrative meaning of an event (things like PC-positive, PC-negative, etc), and then you have to imagine what sort of actual thing fits the bill. Personally, I just find it more useful to randomly generate the actual thing with its narrative meaning to be determined when we see how things play out.

Beyond just the random dungeon, random wilderness, and random encounter appendices, the dungeon dressing tables are a great help. Even in a standard game with a prepared dungeon, sometimes you have those intersections or empty rooms where you have no particular reason to go one way over another. I would say this is especially so in solo-play when you're fully aware the dungeon is pretty much random anyway. So I drop in something at random from the dungeon dressing tables,, including a random direction. So you might spot a broken arrow on the floor of the western corridor. Or you might hear a muffled scream coming from the door to the north. This breaks up the symmetry of the situation, providing clues or even sense of urgency.

An excellent subject, and thread title!!!

I have run Four Against Darkness, but I didn't like the rules, so I just do the 4AD adventures with OSE rules instead.
In general, though, I am more interested to know if there is a good player emulator out there. I try to extensively test adventures before I use them with actual players, but I don't find Mythic very useful, unless it's simply to determine which path a party will take in a dungeon.
If you like Traveller, Zozer Games has a solo guide for Traveller in general (actually for Cepheus Engine, but it's basically the same) as well as one for the Hostile setting.