Spell Prep time and casting mechanics in d100 games

MERP Series
Used MERP collector's edition
Revisiting the MERP round sequence time intervals

In the last post, I specifically looked at the amount of time for each MERP round sequence comparing it with some other games.

In this next few posts, I wanted to begin looking at the actual step-by-step process for resolving actions, specifically the spell casting preparation and casting mechanics of the game. I then contrast it with a few other game d100 systems.

MERP
In MERP, six steps are common and resolved in this order.

1. Prep or cast spell
2. Ranged attack
3. Maneuver
4. Melee attack
5. Movement
6. Static

First is preparing and casting spells.

For preparing a spell, two rounds of preparation are considered the normal (+0) for casting spells. One additional round is needed to cast the spell. Spending more or less time preparing to cast spells results in a plus or minus amount, depending on how many rounds one prepares. A few spells may be cast instantly if so marked with an asterisk on the spell lists.

The penalty for early casting is 1.5 times more incrementally than the benefit of spending extra rounds to caste the spells.

Spells use power points which are based on the stat for the type of magic—Intelligence for Essence and Intuition for Channeling. This gives spell points equal to a number based on the stat multiplied by the character level, if the value is 75 or over. The character must have enough points equal to the spell level in order to cast the spell.

To caste a spell, either a direct or base spell attack table roll is required. Certain base spells, such as force spells, require a resistance roll in order for them to take affect.

So, how does this system compare to other spell systems?

RMX 
RMX (Rolemaster Express) further divides spells into three types of spells based on the characters level versus the level of the spell being cast: these are class I, II, and III spells, in addition to some instantaneous spells.

Class III spells are equal to two levels less than the character level. They require two prep rounds and one cast round.
Class II spells are three to five levels less than the character level. They require one prep round and one cast round.
Class I spells are six or more levels less than the character level

And this means that casting speed is built into the levelling system rather than something chosen.

Spells use power points which are based on the stat for the type of magic—Empathy for Essence and Intelligence for Channeling. This gives spell points equal to the realm stat bonus divided by 10, plus 10, plus 1 per level. The character must have enough points equal to the spell level in order to cast the spell.

The mechanical process is the same procedure as for MERP. Roll and consult either an elemental or base attack table. Some base spells require a resistance roll for the defender.

5e
Classes either prepare spells or limit the number of spells in one's mind.

In contrast to power points, 5e spells use a limited number of spell slots based on one's class or multiclass. This is the primary way of limiting how many spells can be cast, rather than power points. Using higher level spell slots may increase the effect of the spell.

Cantrips are special spells that do not require any spell slots nor preparation to cast.

Spells require either one single action, one bonus action, or one reaction to cast the spell.

Some spells require attack rolls by the attacker or saving throws by the defender.

Star Frontiers
Star Frontiers uses technology rather than spells to achieve superhuman feats. The limits for using the technology are skill levels and computer/technology levels. Sometimes limited resources such as ammo, energy, and doses quantify how many times the equipment can be used.

Equipment cost in credits (Cr) may also limit how much technology a character possesses, since each character has a limited number of credits available for purchasing items.

Game mechanic wise, technology is normally used by rolling under a base chance the character's skill level, minus the opposing level.

OpenQuest
OpenQuest uses magic points based on the character Power score for Battle Magic. For Divine Magic, characters acquire Improvement Points through worship and pay twice the Magnitude value of the spell incrementally. Sorcery may manipulate the magnitude, range, and/or duration as well.

To caste a spell under duress, the character must pass a Battle Magic test, successfully Sorcery Cast, or is automatic for Divine Spells (which can only be cast once until next worship).

Legend
Legend uses magic points based on the character Power score for Common Magic. For Divine Magic, characters use pact which is Charisma plus dedicated Power. For Sorcery Magic, characters use a Grimoire skill. Sorcery users may manipulate the magnitude, range, duration, #targets, and/or combine spells as well.

To caste a spell, the character must pass a Common Magic skill roll, Grimoire roll, or it is automatic for Divine Spells as long as dedicated Power remains.