Spell-Casting: Mana or Spell Slots

By: Jared(Martel)

RPGers!

Today I am looking at the pros and cons of using spell slots vs points aka mana. In this, we will see the benefits of each and how they may be useful, and not, for certain types of play and/or certain gaming systems. We will start with the more well-known spell slots and then go over the mana pool system.

So, spell slots. Most are familiar with this from as early as AD&D. From then on most D&D-like systems and editions of D&D use spell slots, as early as 3rd Edition adding cantrips, as a “freebee” spell type. The gist is that you get so many spell slots of each power level depending on your character level in a given class. Each limits you to only using that many of that power level of a spell before you have to wait for the spell slots to replenish. 

The benefit of such a system is it makes the players more strategic in their use of spells as they want to be careful that they keep their slots, which they think they may need, available for later in the encounter. In my experience, this mixed with having cantrips, means players often hold on to their most powerful spell slots until in dire need of that power level of effect. This also helps the GM as he/she can plan to try and exhaust those slots as resources for the players, allowing the GM to put the right amount of pressure on the players in a visible way as they tick off their used spell slots.

The advantage of this for game designers is that it gives them a mechanic to more carefully balance their classes and their spell power, by limiting the spell slots available to a class and raising the spell level of a given spell to make it harder for the players to use. This kind of spell is then considered more powerful. Also, the game designers can give certain classes limitations. Such as the Warlock only being able to use their highest spell slots first, or the sorcerer being able to use points to shift spell slots from one level to another. This being uncommon in the mechanics as a whole makes those classes unique and adds mechanical flavor to the various classes.

The disadvantage, in my opinion, is the inflexibility it gives the players in the moment of battle to use the spells they really want to use in the moment. With the exception of classes that can manipulate their spell slot availability, the players are stuck with using X:2nd level and X:1st level slots only to find they really wanted to use more 1st level and fewer 2nd level or vice versa. 

For GMs, it means with their NPCs they have to think about what spell slots they would have and keep track of that during the encounters. For me at least, this takes quite a bit of time and forces the GM to be more careful about which spells he/she can give his NPCs and then also keep track of what spells were used so that he/she knows what slots are left.

And game system designers have to take into account all the possibilities and are forced to assign specific levels to spells rather than mana costs and then work it out to make it be balanced so that a spell in X power level is roughly equal to another of the same level.

Now on to the mana pool method. Systems such as the Palladium family of games use spell points rather than spell slots, which they call PPE (potential psychic energy), to show the growing power of their spell-casting classes. With this, typically, you get a starting pool based on some attributes and a few other things, that then will grow with each spell caster class level the character advances in. 

For a player, they can see that steady growth of power reflecting their character’s advancement in the capacity of how many and what spells they can cast in a given time. And then in encounters, they can be flexible in using their spells. Seeing which spells they can use and feeling freer to use the strength of spells they feel that they should without being constrained as much. It also often opens up being able to cast stronger spells than they would be able to in a slot-based system if they are willing to burn all or even most of their allotted points/PPE/mana. 

For GMs it makes it easier to know what their NPCs can do and keep track of the NPCs have left in their capability. Just subtracting mana the way they would for hp, as it is being used. Giving the GMs the same casting flexibility as the players. It also makes it easier for the GM to decide how much mana they want their NPCs to have and what spells they have, a few strong or many weak, to reflect the flavor of the character.

Game designers can be more relaxed in their class design as long as the points pool base is balanced. And they can show more variety in their spells by just having minute changes in spell power with small differences in points cost from one spell to another. 

The drawbacks of the loose and flexible points pool system also fall in all the categories. For the players, it can be too loose. They may find that they can never use all their mana because of odd amounts that they can’t use with any spells and are therefore kind of wasted for that day. For strategists, it can be more laborious for them to plan all their moves, round to round, in an encounter. With less structure as well it can make it harder for them to choose the right spell at character creation or level-ups. 

GMs will find it harder to really know what their players will throw at them with the flexibility to cast whatever the players have points to cast. So planning encounters may be harder and anticipating what the players may do in a given circumstance may make GMing harder than it already is. 

Without the structure of the spell levels, game designers have to find another way to rank their spells so that they can balance them properly. On a type of sliding scale like the point cost system, this can be tricky. Requiring more thought, possibly more effort, and play testing to verify that the point costs can appropriately limit the use of the power of the spells, can be time-consuming. 

With all that, what do ya’ll think? Let us know in the Discord! Thank you for traveling with me once again across systems and seeing what may or may not work with your gaming group! Game On!

About the Author

Jared “Martel” B has been GMing and playing in several TTRPGs since late 2013. Enjoys the challenge of bringing his players’ worlds and stories straight from his mind in the moment that it happens. One of the Founders of RPGCounterpoint, happy husband to an active historian wife, father to two puppers, and soon-to-be father of his first child.