Upon training your character's replacement

I was thinking about the value of a long time scale for fantasy TTRPG adventures, and how it actually ties in neatly with many aspects of old-school style of play:

• Gold-as-xp, and treasure-hunting as the foundational mode of play
• Delves and expeditions
• A slower, more plausible pace of character advancement including training costs for levelling up
• Costs for character death; replacement characters who aren't automatically the same power level as their predecessor
• Emphasis on investing in a base, community, big player-driven projects, and other aspects of the game world
• Social connections, hirelings, delegation, and realm play
• A slower or more 'realistic' time required to recover from injury

Let's say you implement seasonal play, as in e.g. http://udan-adan.blogspot.com/2017/01/the-long-haul-time-and-distance-in-d.html. The PCs have a meagre initial home base. They have some local adventures and make some coin. Enough that they can plan a modest expedition, one that will take months. They come home and spend their wealth, advancing their characters, improving their base, and acquiring the resources for a big expedition, one that will take seasons to complete.

Now let's build on this basis, by adding some game elements to do with character advancement, followers, and character replacement, and see what other common rules might be tweaked.

Character advancement

Character advancement has a cost in looted wealth (e.g., at 1 gp = 1 xp or whatever works with your game rules). Up to half of looted wealth can be used for training; the rest is available for improving the characters' lives and pursuing their goals in other ways.

The requirement that xp must be from looted wealth (e.g. dungeon treasure) ties it back in to the idea that the characters are getting something out of their experiences on delves and expeditions, and also prevents advancement based on capitalism; it feels gamey, but not TOO gamey.

Looted wealth is used to pay for training, tutors, study materials, and so on. Early on, these things are readily available. At higher levels, they might have to be sought out in the world, as it gets harder to find more advanced texts, teachers more skilled than your character, and so on.

Character advancement therefore represents costly, high-intensity learning and study (with an undertone of the character having gone out and had perilous experiences, resulting in both the necessary wealth and the motivation to excel in the training). Advancement takes a long time; let's say a season per level. You could have a more fine-grained system with an increasing time requirement, though.

Followers and character replacement

From say level 2 or 3, players can acquire a number of followers. In D&D-likes, we might say they have followers up to one third of their Charisma score. In those games that already have fleshed-out follower mechanics, you'll need to call them something else or combine the systems.

Followers are just characters like any other, starting at level 1, created with the same character creation rules. They are distinguished from hirelings and other NPCs by an understanding at the table that they are essentially backup PCs; in particular, they won't ever betray the PCs, and they won't be killed 'off-screen' unless the players decided to send them into danger.

Players can invest looted wealth in their followers to advance them, exactly as for their primary PC. This has the same training costs and time and so on. A PC's followers can advance to 1 level lower than the PC and no further.

In-world, followers are squires, apprentices, butlers, bodyguards, family members, and so on. Some of a PC's followers might be their own apprentices (if the same class). But the wizard could retain a loyal housecarl, or the barbarian might have adopted a witch. And some of a PC's followers might be apprentices of other PCs.

The crucial detail for all of this: A player's next character will be drawn from their pool of followers. 

If a player's character is safe back home, the player may choose to retire that character, taking all its wealth and social connections and so on with it. If they choose retirement, the player can have some decent portion of the character's experience transferred directly to their followers, including their new character. Let's say, 50% of earned experience, with no more than 20% allocated to any one follower, and no advancement further than the level of the retiring character. Importantly, the old character then becomes a tool of the GM and is kept out of the way, not a free resource for the remaining PCs to hit up at any time.

But if a player's character dies, the player either takes on a new character at starting level or chooses a candidate from their followers.

Tweaking the rules

This framework works best when the cost of character advancement increases drastically with ever level (as in most editions of D&D). That way, a PC isn't terribly disadvantaged by diverting a split of their wealth/xp to maintain a small coterie of backups.

The GM may need to tweak the total size of wealth awards, and/or give a small bonus to any xp allocated to followers (so that it doesn't feel like the current character is losing out). There should be a balance; players should feel a tension between the risk of investing in their PC and the surety of investing in their followers (in case their PC dies).

Different play groups can organise things differently. One player could pick another's follower as a replacement if they agree, and possibly if a bonus/weregild is paid to compensate. Players could trade followers. A group might decide to divert some initial split of their loot into a set of replacement characters, then treat them as a communal resource.

Followers are also a resource in themselves, providing spells and character abilities and so on, giving additional incentive to invest in them. However, in a world where returning from death is cheap and easy, players won't feel as compelled to 'waste' xp on maintaining a pool of followers. The GM might need to make resurrection spells cost additional wealth/xp, or improve the rate of return on follower advancement, to balance it out.

This system would be easily adapted to a playstyle where everyone plays multiple characters at the same time.

What are the benefits?

So going back to that initial list of old-school play elements...

- Gold-as-xp, and treasure-hunting as the foundational mode of play
- Delves and expeditions
This framework, being predicated on plundered gold-for-xp, puts the focus squarely on treasure-hunting. Having a long time frame and big expeditions also helps emphasise the sheer amount of wealth in the adventure location: it's worthwhile planning a trek across the sea, continent, or world for.

- A slower, more plausible pace of character advancement including training costs for levelling up
- Costs for character death; replacement characters who aren't automatically the same power level as their predecessor
This framework achieves these while offering the players a lot of important choices. The long time frame with seasonal expeditions means that there are regular opportunities for the characters to advance via lengthy training without the pace of adventures precluding it, and without the game devolving into fine-grained in-world scheduling puzzles.

- Emphasis on investing in a base, community, big player-driven projects, and other aspects of the game world
Having increasingly huge amount of treasure in more distant and difficult-to-get to dungeons, alongside increasing wealth costs for levelling up, also helps with game world investment. PCs can do social climbing, come up with their own megaprojects, invest in capital, build fortresses, improve their communities, and so on, with the half of their looted treasure that they can't use for character advancement.

Having an expedition 'off season' (winter) creates room to breathe, and for PCs to get entangled in whatever the player finds compelling: planning, hiring, selling treasure, magic item creation, wheeling and dealing, starting a family, capital investment, politicking, dealing with long-term campaign events, and so on.

- Social connections, hirelings, delegation, and realm play
Expedition-based play encourages use of hirelings, and managing a coterie of followers ties in well with managing hirelings and paves the way to realm-based play. Travelling for a long time to an adventure location necessitates retaining staff or paying friends back home to tend to the character's other, broader concerns while the character is off adventuring.

- A slower or more 'realistic' time required to recover from injury
Not everyone cares about verisimilitude, but for those of us who do, the long time scale and the group of followers together permit a GM to tweak rules and powers towards needing long-term recovery. A character who gets injured has the time required to heal up before the next expedition. When a character is knocked out of a delve due to injury, their player isn't sidelined for a session or two; they have followers with them who can go in instead. Or they can attempt the risky proposition of having their PC continue while seriously injured, knowing they have the backstop of having levelled followers back home if 'injured' turns into 'dead' as a result.

...And finally, as the Against The Wicked City article noted, players will have a chance to actually update the age written on their character sheet.

On edge cases and magic

There's an innate design tension which RPG magic systems must contend with.

Magic must be more powerful than enacting the equivalent effect by mundane means, otherwise it's not fun and not fantastic. But if it's powerful and its uses are limitless (or at least non-rate-limited), then you become committed to an exceptionally high-magic setting.

If it takes ten seconds to give yourself a magical boon which lasts for ten minutes, the default player behaviour and the reasonable in-world behaviour will be to cast the spell every ten minutes... Unless they have a specific reason not to. That's almost always 'resource management'. In almost ever fantasy TTRPG, magic (whether spells, items, rituals, innate powers, etc) will be powerful and limited, i.e., a valuable resource; something to be conserved for when it will matter. Therefore, players will want to know the exact effect of some magic they might use, so that they can make an informed choice.

And this creates a design tension. How predictable to players is the magic their characters are harnessing?

The predictability predicament

Assuming you want magic to be able to do a huge range of things (it's magic), to get breadth of coverage, you either end up with these huge, minutely-detailed lists of magic effects and parameters (almost certainly player-facing), or you have a fuzzy system where the GM instantiates vague wordings at runtime (possibly via what amounts to negotiation with the player). These game design choices have different costs in terms of usability and satisfaction.

Most big, popular fantasy TTRPGs like D&D go with the huge, minutely-detailed lists of magic effects option. This arguably results in greater player agency, in the sense of being able to make good and meaningful decisions about resource allocation, but it constrains magic to the big official list (and if it's not exceptionally well-designed, you end up with weird codified corner cases and interactions). You also need to know the system really well to be effective as a player or a GM. Finally, there's a risk that presenting in exhaustive detail what is possible strongly implies that anything else isn't possible. You get cases like D&D 5e, where many destructive spells officially don't damage objects because a small subset of them specify that they do.

The fuzzy system option is attractive because it makes magic more 'mysterious' and wild, and thus fantastical. But it can be hard for a GM, especially one who isn't already operating in a "rulings not rules" tradition. But it can also be hard for players to come to terms with, unless either (a) it's the case in-world that a mage never knows exactly what they're going to get when they do some magic (which is flavourful, but risks a poor play experience), or (b) the GM and player together determine what happens when the magic is used. The latter might sound good (an opportunity for collaborative buy-in) or bad ('Mother May I' gameplay). Some GMs are surprised to find that many players hate 'collaborative storytelling exercises' spilling over into their roleplaying games. Either way, it doesn't actually resolve the tension: it's still in the player's best interests to stop and discuss the possible magical effect before they can make an informed choice whether to use their magic.

Variants of the fuzzy system where e.g. the GM has to follow certain rules to come up with a power-level-appropriate instantiation of a spell at run-time are close to being the worst of both worlds: mechanically fiddly but without giving a player enough information to make decisions with, and you just end up building that minutely-detailed canonical list slowly over time.

Resolving the tension

I consider this an open problem. As I've suggested before, I think the best practises are to

• Pick a path and stick with it, rather than mixing up how rigid and predictable the magic system is in different use-cases within the same game; and
• Have an extremely strong, well-thought out metaphysics which either underpins the mechanical design for the minutely-detailed lists option or informs what 'should be the case' for the fuzzy system option.

Food for thought

Here are some questions your magic system must be robust enough to answer, consistently:

If you turn flour to silver dust and mix it into acid, changing it to silver nitrate and creating heat, what happens to the silver nitrate if the spell wears off? What happens to the heat? If the compound is left over, can you reduce it to get silver? Does the resulting silver still count as being magical?

If you turn a pile of stones into loaves of bread and spend a week eating them, what happens to your tissue, the partially-digested bread, and the waste, if the magic ends? Do you die instantly? Does the energy you got from eating disappear?

If you turn a stone into a cat, and that cat eats and sweats and breathes makes waste, then the magic is dispelled, what happens to the bits of world (food and air and water) that got incorporated into the cat's body? Are they in the stone? Do they turn to stone? Can they be turned back? What happens to the cat's sweat and waste and loose hairs and skin particles out in the world? Do they turn to stone? What if the cat was a kitten, and it grew much bigger and older before the spell ended?

Or if the original subject was a mouse rather than a stone, what happens to the cells that changed in its body? Was there a 'mapping' from one mouse cell to multiple cat cells, so that injuries and shed cells and replaced cells carry back over? Do microbial diseases carry back over? Does cancer?

Are all your answers consistent so far?

What happens if you turn someone into a statue and snap their arm off? What about if you turn someone into steel and then temper or anneal the metal? Or take a mould of their body, turn them into ice, melt them, and then refreeze the water in the mould?

What about if you turn a piece of metal into a piece of wood and burn it inside a big tank of air? Does the carbon dioxide turn into a metal oxide? In general, if you heat something up while it's magically transformed and then turn it back, is it still hot? What if you turned something really small into something really big and then it just got slightly warm by soaking up a million times more sunlight than the tiny thing would have?

If you expand a mouse to be the size of a horse and it eats a bucket of oats, what happens to the oats if it turns back? Does it matter whether they've been digested?

If you expand a mouse to be the size of a horse inside a mouse-sized terrarium that a mouse couldn't possibly break but a horse easily could, does the spell work? Does the answer change if the terrarium is nearly horse-sized? What about if you try it on a mouse that's inside a crack in solid rock? Is this meaningfully different from trapping a mouse under a piece of heavy cloth and then expanding it to the size of a horse?

If you cast a spell on a subject, then another one that seems to have the inverse effect (flesh to rock then rock to flesh), do you get back the exact original? If so, why? If not, what happens if only the first spell ends or is dispelled? What if you cast the first spell, then make some orthogonal change to the subject, then cast the second?

What in-universe mechanism decides whether an object counts as meeting the targeting requirements of a spell? Does a spell that works on chairs work on a one-legged stool if the caster doesn't think a one-legged stool is a chair?

Do any of the answers to these questions change depending on whether it's a temporary effect, a dispelled permanent effect, a magically reversed effect, an intrinsic ability of a magical creature, the effect of an item, etc?