Rather than the replacement for techniques being certain roles learning new spells from nowhere once you achieve a certain experience level, have the spells be known from the beginning, but uncastable unless you are above that level.
This also helps disincentivize drain-for-gain tactics, since keeping yourself at a lower level will cut off your access to certain spells.
Add a system of “hell curses”. When you enter a demon lord’s lair, you are afflicted with 2 random curses, which stick around forever until the lord is killed or bribed off.
You can receive at most six curses over the course of the game, requiring you to defeat the lords of the first three lairs you encounter. Further generation of lairs does not add any curses.
A non-comprehensive list of potential curses is:
Wearing the Mitre of Holiness removes the spellcasting penalty from wearing a shield.
A spellbook will teaches you one of 4 ways to cast the spell, randomly chosen and deterministic per-spellbook:
Various conditions prevent you from casting a spell if you are limited in how you can cast it: choking and being polymorphed into a form incapable of speech (etc) prevent you from casting a spell you only know how to cast verbally, and being held or stuck to a monster or having both hands welded to cursed gear (etc) prevents you from casting a spell you only know how to cast somatically.
You can read additional spellbooks to “upgrade” your casting ability in addition to refreshing your memory: e.g. if you can cast force bolt somatically but don’t need to speak, and you read a spellbook of force bolt that teaches how to cast it verbally but not somatically, you become able to cast it fully at will.
The motivation for this is to make large quantities of obtained spellbooks containing many duplicates of already known spells more interesting.
Not specified how the hero knows how to cast their starting spells; obvious options are:
Alternative Necromancer role, because its implementation in SLASH’EM winds up being a rather halfhearted version of Wizard with some elements of Priest and Archeologist. Note: This was written for a hypothetical variant that does not have a Necromancer role, rather than as an update to SLASH’EM’s.
The system may want some simplification since it may be clunky to have the player navigate through menus to choose souls from all the different ones they have accumulated. Possibly, souls from a given species just combine, so you would be shown something like “souls of gnome kings (12 total monster levels)”. An extreme simplification would cut out the entire soul-storage system and just replenish Pw when you collect one.
Wizards can talk to the apprentices in their Quest home level to pay them for learning (possibly only low-level) spells. These are provisionally priced at 50 times the spell level times the player’s level, and is intended to serve as a dilemma for whether to buy spells or protection. (However, a single point of protection would cost the same as 8 total levels of spells, so the cost may need to be raised.)
Cornuthaums give a lesser reduced-hunger casting benefit to non-Wizards who wear them. They also improve reduced-hunger casting for Wizards.
Cavemen receive a spellbook of fireball as their crowning gift, which they can always cast with 100% success rate. Flavor-wise, this ties into “discovering fire”.
Allow wielding some types of traditional magical implements to reduce spell failure rates:
Add a system for casting ritual spells: more powerful and more expensive spells which have some esoteric effects you can’t get otherwise. The main differences between ritual and normal spellcasting are that they consume valuable, hopefully non-renewable components, take a number of turns to cast instead of taking effect instantly, and may require you to be in or set up certain circumstances.
Various ritual spells that have been proposed:
Ritual spells come in spellbooks like usual, but aren’t stored in your spell list. Instead, reading the spellbook prompts you if you want to begin its ritual and tells you the necessary ingredients and circumstances you need to satisfy as preconditions. If you meet all the conditions and answer yes, you initiate the ritual. (For simplicity, this should probably burn up / expend all the components instantly.) You cannot begin a ritual while in the process of casting another ritual; this should probably be implemented as a precondition.
Apart from the component cost, rituals act as a constant drain on your Pw until the ritual is complete. If something distracts you in the middle of the ritual, you can go take care of it and then resume the ritual as long as you have the Pw left to finish it. (You could also drink gain energy during the ritual.) The only way for a ritual to fail, possibly backfiring with bad effects, is for you to run out of Pw while it is incomplete.
In addition to its preconditions, each ritual also has some postconditions: common to all rituals is that you have been casting the ritual for at least some length of time, but there may be others, such as standing on the square where you began the ritual, or have another item, or kill a monster, or something. There may also be other conditions such as “moving off the space where the ritual started breaks and halts the ritual”.
Every time you stop casting a ritual (whether it succeeded or failed), it increments the spellbook’s spestudied field; the book will eventually disintegrate after casting it a certain number of times.
Advanced spell forms are slightly problematic. Certain spells (fireball and cone of cold) which have advanced versions automatically kick in when the player is Skilled or above, and can’t be cast using the lesser form even if the player wants to.
It’s a problem that utility spells with a high failure rate, such as identify at 95% fail, is a mere inconvenience to players, since they can sit in a closet with a stack of food and wait for their Pw to recharge until they succeed. This is not really a problem with combat spells, since the penalty for failing to cast the spell correctly is a disadvantage in combat, where time and Pw matter. Some possible ways to address it:
real Pw = base Pw / success
rate. Under this formula, a 15 Pw spell at 95% fail becomes a 300 Pw
spell at 0% fail. This means the Pw cost should be exposed in the spellcasting
menu rather than failure rate, even though failure rate still needs to be
calculated. Maybe use different colors in the spellcasting menu to denote
spells you can cast now, spells you can cast by waiting to recover more Pw,
spells you can’t cast even at your current maximum Pw, and forgotten spells.The wield slot is fairly underused among object classes, and there are a number of interesting bonuses we can add to spells if the corresponding spellbook is wielded.
Cantrips are level 0 spells that cost d2 or d3 power to cast. In order not to let them be unbalancing, they don’t train skill and are mostly useless, except in certain circumstances or for low-Pw spellcasters who can’t do much of the bigger stuff yet. ais523 suggests that good candidates for cantrips might be things that have little combat use, and whose effects could be duplicated by backtracking or other tedious things, but would be useful to avoid boredom. Given their cheapness, they should probably not train skills, and may not even need spell schools.
Most ideas for cantrips seem to be a little too powerful and would do better off as normal spells (and may be listed as independent YANIs for normal spells); however, those that seem like they would fit are listed here.
Differentiate spellcasting greatly for the different types of spellcasters:
Cartomancers don’t spellcast using Pw. Instead, they read the book (which is instantaneous for them, and possibly subject to a failure chance like normal if the spell is not known) and the spell immediately takes effect. This increments the read counter for the book, so each book can be used to cast a spell 4 times before it blanks.
The dunce cap inhibits spellcasting (on top of the low intelligence it provides; not specified if it should entirely block spellcasting or just make it very difficult) but also provides magic resistance when worn. This is to add diversity of non-artifact magic resistance builds for non-spellcasters, and also to allow people to give magic resistance to pets that are incapable of wearing cloaks.
Peaceful monsters casting spells do not interrupt multi-turn occupations.
Worn shields of mobility do not apply a shield-based penalty to spellcasting, since they are by design supposed to aid your mobility.
Using a spell staff allows you to cast spells of the associated school while not necessarily being able to speak (due to polyform or some other reason); it could also potentially suppress other impediments to spellcasting, such as confusion.
A silence spell for either players or monsters or both. Not specified whether it would be area-of-effect or targeted at specific creatures. The main function of silence effects would be to prevent spellcasting. Not specified whether this would also affect reading scrolls (though probably not since you can “cogitate” the formula on scrolls if polymorphed into a speechless form).
However, this may require defining certain existing spells as not requiring speech, because it does not seem entirely fair to take away all of someone’s escape or healing spells with fairly low level magic.
Object properties, one per spell school, which each give you a casting boost in their spell school when the item is equipped (it only generates on equippable items). Should be rare compared to other object properties, and unwishable.
Eating the brains of a spellcasting monster should restore some magic energy, and perhaps even have a chance of learning a spell from its brain. (This latter part would work better in variants such as FIQHack where monsters have a list of player spells).
Certain high level spells require some minimum amount of skill in their school in order to be able to cast them at all. For instance, create familiar should be impossible to cast if you are not at least Basic in clerical spells, perhaps even Skilled, no matter what you do to improve your spellcasting odds.
Evil librarian monster: it is peaceful at first, but considers every spell you know to be an overdue library book, and charges you a $100 late fee per book when it encounters you. If you don’t pay, it attacks. Possibly they carry some books, and if you manage to keep it peaceful, you can loan books from it. May generate with a magic marker.
Casting spells decreases your spell memory by a small amount but one that would be significant if you cast the spell heavily.
Ring that provides magic resistance, but hinders your own spellcasting while you wear it by increasing your spell failure rates. Additionally, it gradually drains your magic energy while being worn. If you have no energy, the ring stops providing magic resistance.
The Amulet drains your power when you cast spells, even if you’re not carrying it, if it’s on the ground nearby. The amount of power drained is proportional to your closeness to it.
A dungeon feature that massively improves your spellcasting success rates while you are standing on it.
Remove Wizards’ exclusive access to reduced-hunger and hungerless casting. Instead, tie spell hunger to how experienced you are with the spell; this could either track how many times you’ve cast that specific spell, or use your skill in the spell’s school as a proxy for that, or both. Intelligence could remain a factor, but the important thing is that non-wizard casters can also enjoy the benefits. (Note that Wizards, what with casting spells a lot more than other roles and having high spell skill caps, will still reap a larger benefit from this.)
One possible failure effect for reading a spellbook (or writing it, if it’s possible to fail at writing a book) is for the spell to force itself into your head. Your spell retention is internally -1, a special value that means you can cast the spell, but only once, and then you immediately forget it.
An enchanted spell stave will boost your spellcasting in its school, with a greater boost the higher the enchantment is.
Spell staves are made into poor melee weapons (comparable or worse than the club, being basically a stick that’s just sturdy enough not to break), but are made lighter than the quarterstaff, weighing only 10. Its bonus to a single spellcasting school is countered by it applying a slight spellcasting penalty to spells of some or all other schools.
Implement a player fear system that unlike many other proposals, does not take away agency from the player by paralyzing them or forcing them to flee using a predefined algorithm. Instead, it incentivizes the player to flee by making continued combat unattractive.
Create a new intrinsic called “Panic”/”Panicking”. Sources of fear (including existing sources of paralysis-fear, e.g. ghosts) give you temporary amounts of this intrinsic. While you are panicking:
If you have confusion charges from the scroll or spell (meaning your hands are glowing red), the Z menu will gain a “confuse” spell option that always has a 0% failure rate, with the associated key being “-“. Casting this allows you to “zap” a confusion charge in any direction, confusing the first monster it touches.
The player can’t cast spells or use magic items while standing on top of an anti-magic field. (Rather than straight up not being able to use the magic items, they would behave either like their non-magic counterparts, or as if they had no charges, as much as possible. Magic instruments would play normally, wands would fail to produce an effect, scrolls would have no effect, and so on.)
For role differentiation: each role can only learn up to a certain number of spells. Wizards can learn them all, while roles like Healers can learn about a dozen; valkyries might be able to learn 3 and barbarians 1 (or 0). Possibly combine this with #2084.
The player can never learn, or can learn but never cast, spells that they are restricted in.
Trying to cast a forgotten spell and getting nightmarish images in your mind drains a few points of Pw.
The base Pw cost for a spell is specified per-spell, and only correlates with spell level rather than being tied to it, which allows for interesting things like low-level spells that are easy to cast but expensive.
Spells now take different numbers of turns to cast (interruptable by normal means). Combat spells and some of the emergency spells still take only 1 or 2 turns, but utility spells can take up to five or so.
Deafness multiplies your spell failure rate by a constant amount, due to maybe not getting the pronunciation right because you can’t hear yourself.
Factor your role’s skill cap in spells’ schools into the success rates for those spells.
Spells can be “bound” together so that they can be cast simultaneously.
Armor made of bone increases your spellcasting ability somehow (many ways to do this; decrease failure rate? Decrease Pw cost?)
Higher skill in a spell school allows you to subtract some points off its Pw cost.
Ring or amulet that causes your spellcasting to draw on HP instead of Pw, possibly only when your Pw is zero, or possibly not requiring a ring. Each point of HP is worth 2 Pw points. If cursed, doubles spell Pw costs. If blessed, energy regeneration will regenerate HP until full before regenerating Pw. Casting from HP too much may decrease your HP maximum. If implemented as an artifact, possibly flavor it as an evil counterpart of the Eye of the Aethiopica.
Note that a couple variants have implemented this as a “ring of blood magic” or similar items.
Casting a forgotten spell consumes some Pw, perhaps one point per spell level, or just a random amount, in addition to its confusion and stunning effects.
Hands holding a quarterstaff or wands don’t count as being occupied for the purposes of calculating spellcasting penalty. (Perhaps generalize wands to any other non-weapon.)
To avoid the annoyance of disrobing in a closet to cast utility spells, mark certain types of spells as being non-combat, utility spells. Such spells have a much reduced armor penalty, but take several turns to cast.
Reorganize which roles get which special spells, based on the change that every role should always have a 0% failure rate at casting its special spell.
If the metal spellcasting penalty were to be removed entirely for one armor slot, it should be the boots slot, because your feet are very distant from the magical casting part of your body.