MP Costs

[jonthefox]

When I say MP I'm referring to whatever resource your game uses that limits skill usage, whether it's called SP or something else.  I'm also referring to the resource that all skills cost, not just magic.   So even a warrior or rogue have to manage their MP (or whatever resource their skills use). 

How do you decide these costs?  Obviously, things like the availability of items and spells that recover MP must be factored in--but these are adjustable in whatever way you want.  As a game designer, you have pretty much total control of over how costly you want your skills to be in terms of their mother resource.  Too high costs would probably leave a player frustrated, and too low costs probably defeat the purpose of gating skills in the first place.  How do you determine a good balance?  Should it be just enough to get through a dungeon + a little bit of breathing room?

 

[bgillisp]

I think it depends on how high your MP is in the first place. If your actors have MP in the 100 - 200's, MP costs of 1 - 2 make little sense. On the other hand, if your actors have only 25 - 30 MP normally, then MP costs of 1 - 2 would make sense.

So what I'd do is start with my actors MP gauges, and set that. Then from there, I balance my costs around how much MP my actors will have (on average) at the point I learn the spell, and how often I want my actors to be able to cast it before using an MP restorative or stopping to rest. Usually this does mean it results in you using most of your MP to clear a dungeon, with a little for breathing room. However, early in the game I make an exception to this rule, as the player is learning the system, and then my dungeons will usually only use up about 50% of your MP, and maybe not even that much.

 

[gstv87]

think percentages and seconds.

I designed my skill set from an already established set of skills from an MMORPG, and their skills grow in cost as the player levels up.

long story short, one of the default wizard skills costs 70 MP, out of a maximum MP for that character of 3600.

that's 2%.

his MP regeneration is a fixed 9 points when maxed out, that's 0.25%.

so, it takes him 400 seconds to recharge completely... that's almost 7 minutes.

in online play, 10 minutes is more than enough for a short break, but in combat, it's an eternity.

focus on the lowest value available (in my case, 9 per second).... multiply by the amount of seconds you want to spend, and divide by the top amount of hits you want to allow.

I don't believe you can add fixed amounts in VX/MV, only percentages, but the logic is still valid

 

[Wavelength]

There are a ton of different situational factors that make trying to answer this question a moving target (Can the resource regenerate?  Does it fill after each battle?  How long are dungeons?  Are there dungeons?  How important is the hidden resource of the character's "turn"?).

However, I think two tenets should be almost universal in coming up with costs:

• Resource costs need to be balanced across different skills, using the Normal Attack at 0 MP/TP as a baseline.  So if a 20 MP skill gives you 30 "utils" of extra damage or utility and a 40 MP skill gives you 50 utils, the 60 MP skill should probably give you around 65 utils (making for a balanced diminishing-returns curve).
• Resource costs should be high or low enough so that characters who use fewer resources (usually warriors/melee types) have clear advantages and clear disadvantages in different situations, compared with character who use more resources (usually mages, archers, or item users).

 

[Alexander Amnell]

   It depends on how skills work in your game. For instance, in my game the minimum stamina (or non-magic resource) cost for a skill is 5% (using an edited version of aces tp to the effect, so max is always 100) and that's just the normal attack that in most games is a free resource. The rest of the skills cost between 15-70% of the character's max stamina a piece, which on the surface would be completely unbalanced except that each character and enemy restores 10% stamina at the end of each round which can be buffed by an additional 15% by taking a turn waiting/guarding. While that works, the point I'm trying to make is that deciding what your abilities cost depends entirely upon how the battle mechanics in your game are set up and thus you won't find a cookie-cutter formula that works to follow unless you base your game off of another already established system.

   Best advice I can think of is this; figure out how your battles flow and battletest religiously under multiple scenarios. The best way to find out if your skill costs are right is to experience them as a player yourself, it's also the best way to weed out over/underpowered skills as well.

 

[Zoltor]

Well I have 3 types of skills open to every char(this Isn't counting any unique skill type, which will replace the standard Magic skill type on said char).

Basically characters have magic, special skills, and techniques.

Magic(and any unique skill type that replaces such) uses MP naturally, which is plentiful, such skills aren't all that powerful, but you can use them whenever, likewise most of the support/status effect skills are relegated to this as well.

Special, and Technique skills both use TP(note: I have TP set to remember), but are handled completely differently.  Special skills are tied to specific pieces of equipment, and ocupi most of the more powerful skill in the game, but that being the case, you need a decent amount of the TP bar to be filled(in many cases, you'll actually need 100% of such filled).

Now Techniques are not only, not equipment specific, but the player has the freedom to make any char they want, learn such. Now much like the special skills, these tend to be very powerful, and use TP in the same way, however to make a char learn a technique skill, you need to find technique scrolls, which are usually only dropped by high lv enemies or high lv special chests, both at very low rates(in some cases, you'll even be required to craft a technique scroll out of finding scroll fragments)

TP by default if you set it to remember, works like the Lufia games, which makes it very easy to balance(players are going to be expected to use such sparingly, since using them whenever, will make then unusabe in situations that such would come in very handy) As for magic, since the more powerful skills wont be available, It's really just a matter of figuring out how many times I want to allow a char to cast heal or buff skills at certain levels(the damage doing magic skills will likely have the cheapest MP cost, since if characters have dmg based magic type skills, that will generally be their main form of attacking, which is no different then a warrior attacking with a sword, so yea I want to make sure players don't have to worry about such eating up too much MP for what they do).

 

[kranasAngel]

I personally have relatively low MP costs, but try to make use of cool downs as much as possible. By giving every skill a cool down of some sort, I can prevent players from spamming skills while still keeping magic costs low

 

[Fernyfer775]

I personally prefer MP costs that are a set percentage.

For example, Fireball costs 5% MaxMP + 10MP, that way, as the user levels up and gains more Mana Points, so does the cost.

If you balance it right, as the character levels up, they will be able to cast more spells than they were able to at level one, but it also avoids the problem of having spells that cost 10mp, when the character has like 500mp at end-game.

 

[Wavelength]

I personally prefer MP costs that are a set percentage.

For example, Fireball costs 5% MaxMP + 10MP, that way, as the user levels up and gains more Mana Points, so does the cost.

If you balance it right, as the character levels up, they will be able to cast more spells than they were able to at level one, but it also avoids the problem of having spells that cost 10mp, when the character has like 500mp at end-game.

I feel like this would feel unrewarding as a player.  Yeah the absolute "10 MP" cost in there is preventing Max MP from being a useless stat, but I feel like it would still be a dump stat.  Are you also making all damage do "% Max HP" to a character when hit?

The "10 MP out of 500" is absolutely an issue but I'd usually expect that to be handled by either keeping Max MP constant (or almost constant) throughout the game or by having the power and cost of all spells increase as you level up.

 

[TheHonorableRyu]

This is a rather loose and relative question without knowing more concrete details about the kind of RPG we're talking about.

 

You're right that "Too high costs would probably leave a player frustrated, and too low costs probably defeat the purpose of gating skills in the first place," but balancing numbers to find that happy medium is a fine-tuning process that is best taken on once other variables are set in place.

 

Wavelength's advice on "utils" is very good for balancing skill costs relative to one another, but balancing how much a skill should cost relative to the user's maxMP is going to be highly independent on a host of other variables and the effect you're trying to achieve.

 

How often can the player restore MP, and for what cost(s)? Are there any other kinds of resources (SP, items, etc.) besides MP the player's characters can fall back on when MP runs low? Are there dungeons? How long are they? Can the player restore MP within dungeons, and for what cost(s)? How imperative is it for the player's party members to use skills that cost MP in order to win battles? Is this for most of regular battles or only for tougher regular battles? Does the game require the player to conserve some MP to have a shot at defeating dungeon bosses? Do skills have other costs such as cooldowns? Do you want all the characters to be reliant on MP to some extant, or are some fairly effective even without MP? Do you want some characters to deplete their MP faster than others? How wide a range of effects for the MP cost will the player have access to at a given time in the game (e.g., will they have an option to deal double, triple, or quadruple damage per turn for increasing MP costs, or only 1.5x, 1.75, or 2x damage per turn)? Etc., etc.

 

Dungeon crawlers like Etrian Odyssey series, Shin Megami Tensei: Strange Journey, or Unchained Blades often have long dungeons, fairly tough enemies, and very few options for MP recovery inside dungeons. Once the player's characters start running out of MP (especially on healers) they'll have to turn back, heal at an inn, and retry the dungeon, hopefully with more EXP and resources/equipment to get further on the next run. Balancing MP costs for a grindy dungeon crawler is obviously going to differ compared to a game where the emphasis is forward progress and MP can be fully restored for free or relatively cheaply at every mid-dungeon save point (as in Grandia 2 or Chrono Trigger). So if we had more information about the kind of RPG you want to create we could have a more helpful, in-depth discussion. 

 

[gstv87]

The "10 MP out of 500" is absolutely an issue but I'd usually expect that to be handled by either keeping Max MP constant (or almost constant) throughout the game or by having the power and cost of all spells increase as you level up.

don't forget that *spell efficiency* is also a thing.

you should balance the cost to the damage or chance of landing, so if you cast a low level spell against a high level enemy, it might not do damage at all.

likewise, casting a high spell against a low level enemy, might be overkill.... so, one tool for each job, I guess.