Om Magike for M20-ish

I had mentioned Om Magike as a project for Andras previously. I have since found that doing the crunchy stuff in Microlite format helps me get to the point and stop writing a bunch of flowery prose that can't be used in a game.

Why M20-ish? Because it uses my d20+d10 mechanic. I've called it M2010 in other places, but will call it M200 for this point on. The 200 is what rolling a 30 will look like. Two hundred is also the number of possible die rolls using d20+d10. As mentioned previously, rolling d20+d10 provides an interesting bell curve as well as other possibilities in opposed rolls.

One last thing to mention: the text of the post is alpha. The downloadable pdf will have been edited. Today is the grand theory of magic and some crunch for the various classes. The next post will have examples.

Overview of Magic

The use of magic exists along a continuum. At one extreme, there is an intuitive understanding of the essence of magic. The force of magic in the universe is an organic part of the universe and exists inside everything. In this extreme, magic is a relationship between the spellcaster and the universe. The nuts and bolts of how magic works remains an awe-inspiring mystery. Practitioners of this type of magic are called Thaumaturges. At the opposite extreme, magic is a force to be wielded. Magic is controlled by precise ritual. These rituals are discovered through careful study and exacting experimentation. For spellcasters in this end of the continuum, magic is a skill in the same way that working leather is a skill. Practitioners of this form of magic are called Arcanists. Near the middle of this continuum are Wizards. They have the trappings of the Arcanists, specifically books with arcane formulae, various experiment, long hours of study and the like, paired with the outlook of the Thaumaturges. In other words, Magic is seen as a force that is barely understood. It is not controlled, but can only guided through a relationship with the force of magic itself.

Races for Magic Using Classes

Thaumaturges are rarely human or dwarvish. Most are elves and other fey creatures. Human spellcasters tend to be Arcanists. Dwarves, Gnomes and Halflings can also be Arcanists. Exiled Elves can also be Arcanists; details about Exiled Elves will be provided in more detail elsewhere. Wizards are always human or half-human, but uncommon. Wizardry was discovered/invented by a human many generations ago. Its usage has a relatively short history as compared to Arcany and Thaumaturgy. Powerful Wizards are greatly feared as their power has the potential to exceed that of the eldest Elven thaumatuges. Despite this, Wizards are sneered as either too sloppy in research or killing the beauty of magic through that same tortuous research.

Miracles or Divine Magic

The working of miracles also exists along a continuum. Priests align themselves with a chosen deity or pantheon and draw power from this relationship to work miracles. Purists (called Psions by Priests) search for power within the Soul and draw power from it to manipulate the universe. Purists do not believe that they are performing miracles, but to common folk, the distinction between a Priest and a Purist is minimal. Both spend time in meditation to recharge their ability to work wonders. Between the two extremes are the non-human shamans. Shamans gain power from many different places, including primal forces of nature, deceased ancestors, collective consciousness, unique landmarks, and more.

Shamans are differentiated from Priests and Purists by their ability to invoke the sources of their power directly. Their invocation usually takes the form of hours-long rituals, using rare materials and a vast number of songs. These powerful invocations have been known to make entire villages disappear or cause the ground to roil beneath an invading army's feet.


Thaumaturges are able to use magic governed by their Magnitude and Mana. Magnitude is a measure of the character's level of power and the potency of magic. Mana is the character's reservoir of metaphysical energy and the Thaumaturge's connection to the source of magic.

Magnitude influences both the spell levels that can be cast and the spell's casting cost in Mana.

Starting Mana is Magnitude + MIND Stat. At each level, the Thaumaturge adds their MIND bonus to their Mana.

The cost for casting a spell is Magnitude + the Level of the spell.


Full Casting is when a character unleashes a spell with her full capacity. The amount of Mana required is equal to her Magnitude + Spell's Level.

For example, a 5th level Thaumaturge casting Magic Missile with this method allows the spell to function normally. The character's level determines its range and other bonuses. It would cost 4 Mana (3 for her Magnitude and 1 for the spell's level) to cast the spell.


Demi-Casting can be used when a character is trying to conserve Mana, or only needs less than the full mana required to cast a spell. The Thaumaturge may selectively reduce his or her Magnitude, as long as it is not lower than the Spell's Level. The benefit is that the Mana required is less than normal. However, the drawback is that the spell is considered casted at 2 levels lower for each 1 point of reduction in Magnitude.

For example, if a 7th level Thaumaturge casts Magic Missile uses full casting, the spell to functions normally. The spell is cast using 7th level to determine range and other bonuses. It would cost 5 Mana (4 for her Magnitude and 1 for the spell's level) to cast the spell. To cast it with less Mana, using only 4 Mana, the effective casting level would be 5h level. Using only 3 Mana, the effective casting level would be 3rd level.

Demi-casting is also used for spells that do not have level-based effects. Knock is always cast as if the Thaumaturge lowering their magnitude to 2. For all Thaumatureges, casting Knock always costs 4 Mana (2 Magnitude plus 2 for the level of the spell.)


Thaumaturges are able to create a periapt that can store Mana. A Thaumaturge can create a periapt that stores up to the thaumaturge's Magnitude in Mana. Thaumaturges can use any periapt with stored Mana, even if the amount of stored Mana exceeds their Magnitude.


Arcanists has a new skill called Spellcraft. When attempting to roll under the target number given for a spell, the Spellcraft rank can be added to the target number.

GMs Note: This requires that all spells have a difficulty rating. Using the Spell Creation system, spells may vary in difficulty ratings, including numbers over 30 and less than 2. In general, use the table below to assign difficulty ratings to spells:

Spell Level Difficulty Rating
1st 30
2nd 25
3rd 20
4th 15
5th 10
6th 5
7th 0
8th -5
9th -10

Arcanists take subdural hit point damage per standard M20 rules when successfully casting a spell. When a spell fails, the Arcanist loses 1 hit point and may attempt the spell again.

Optionally, an Arcanist can also use the Mana rules like a Thaumaturge. Arcanists, however, cannot create periapts to store mana.


As per standard M20 rules.

Opposed Rolls

Before going into a post likely to be snored off, I wanted to thank Kevin Sullivan for the stats he generated on this site. The presentation of certain things are more clear there. He also provided me with a good idea on how to generate Class XP tables for Andras.

I had posted on Google Plus about a shortcut method of performing opposed rolls. The numbers do not come out the same, but I figured that they were close enough. What I discovered in studying these numbers points to effects of specific designs. In the end, I think that my design doesn't produce results that are always similar, but that produces results more in line with my design philosophy.

Specifically, the results show that:

  • Characters with equal bonuses to skill rolls under Microlite20 will have a similar, but varied chances of success under my system.
  • The Microlite20 system is affected by relative adjustments to the roll. My system is affected by the actual skill ranks and Attribute score.

Here is an example using the Microlite20 rules as written and comparing to my system.

Listen is Subterfuge + MIND.
Move Silently is Subterfuge + DEX

Aesir is attempting to sneak up on a guard. Aesir has a 16 DEX and a Subterfuge rank of 2. The Guard has a MIND of 12 and a Subterfuge rank of 4. According to the rules, the one with the highest roll wins. Each character receives a bonus to their individual rolls of Skill Rank + Attribute Bonus.

For Aesir, we get 2 (skill rank) plus 3 (Attribute Bonus in M20) to get 5.
For the guard, we get 4 (skill rank) plus 1 (Attribute Bonus in M20) to get 5.

Given these stats, Aesir will succeed 47.5% of the time. The guard will succeed 52.5% of the time because he will win all ties. By rule, ties go to the character with the highest skill rank.

Under the Microlite20 system, the chances of success will not change if the guard has a Skill Rank of 5 and a MIND of 10, a Skill Rank of 3 and a MIND of 14 or a Skill Rank of 2 and a MIND of 16. The adjustment to the roll remains +5.

In my system, success is determined by rolling-under the total of the Skill Rank and the Attribute itself. When performing an opposed roll, the Player Character has to subtract half the total of the NPC's skill rank and attribute. In this example, Aesir's Subterfuge rank plus DEX is 18. The guard's Subterfuge rank plus MIND is 16. Success is determined by Aesir rolling equal to or under 10. In other words, 18 minus 8 (half of 16). This give Aesir a 50% chance of succeeding. This is a slightly better chance of succeeding than with the Microlite20 system.

What I found surprising is that if the guard is changed as I mentioned earlier, Aesir's chances of success are affected.

sub MIND Aesir Wins
Guard 1 5 10 52.50%
Guard 2 4 12 50.00%
Guard 3 3 14 47.50%
Guard 4 2 16 45.00%

All four of these guards are identical according to the Microlite20 system, but the results are slightly different under my system. Nothing is really dramatic in the results, even with very improbable NPCs (do you hire MIND 16 guards? Would a MIND 10 guard have a 5 subterfuge skill?)

For the sake of completeness, let's say that Aesir is opposing a lower skilled guard of average intelligence. Subterfuge skill rank of 2 and a MIND of 10. Under the standard Microlite20 system, Aesir has a 62.5% chance of success. Ties no longer go to the guard, but they don't go to Aesir either because there would be a re-roll. Under my system, Aesir has a 60% chance to succeed.

Why does it give a worse chance? The amount of change is less in my system. If you compare the original example, Microlite20 provided no advantage to Aesir. He and the guard were equal. In my system Aesir had a slight advantage, thus a higher chance for success as compared to M20.

Changing to scores provided Aesir a great advantage. Instead of being even with the Guard, he now enjoys a +3 advantage. That big of an advantage yields bigger results. In my system, Aesir already had an advantage over the first guard. Changing the skill and MIND score had less effect because the amount of advantage changed comparatively less.

Somehow I'm Awake, What Does All This Mean?

Advancement in Microlite20 provides for increasing Skill Ranks and Attributes. This makes the characters very high powered around 10th level. In my variation of M20, characters cannot change Attributes except by magic or optionally by age.

I hope this means that characters can be fun to play for more than 10 levels.

This also means that using Microlite20 as a platform to develop Andras helps me get the bones of the system working well. This will be easier to playtest, especially for newer GMs. This also allows me to playtest a solo version of M2010 (my system). Maybe I have been reading too much T&T lately, but having a solo version plus the Mythic GM appeals to me.

As always, more later.