How to create elemental ninjutsus

In general, elemental ninjutsus are more powerful than tai and genjutsus which is why they have the highest BP and stamina costs. Taijutsus have lower BP costs but roughly the same stamina cost, Genjutsus have low BP and stamina costs.

This is the guideline I follow when creating elemental ninjutsus.

Its all about the ratio between BP cost, Stamina cost, attack/defense power and the other variables.

If a jutsu has high attack and/or defense power then it must also have high BP cost and/or stamina cost. Lower one, increase the other and vice versa.

For example, lets say you want a powerful jutsu that you can cast at moments notice in case someone surprises you. A low BP cost and high defense power would mean that jutsu would have to have a HUGE stamina cost. If you want a lower stamina cost you'll have to lower the atk/def power or increase the BP cost or give it crappy effects or a very small range.

Just so you know, range is measured in meters. Imagine the battlefield like a grid in a turn based strategy game (like Heroes of might and magic or Final fantasy tactics) and ninjas can only move on grids. Each grid is 5 meters apart and all movement actions are done in terms of 5 meter movement (meaning a ninja can move 5, 10, 15 meters... but not 4 or 6 or 13...). When choosing the range coverage for a jutsu bear in mind that it should reflect on how the jutsu looks like in the anime/manga and that the greater the range coverage the more you'll have to nerf the other variables. You can't use an exploding jutsu in melee range now can you?

Anyway, you get the idea. Now here are some guidelines you need to follow when making each jutsu:

-D rank elemental ninjutsus should have 1~2 BP cost, 1~6 stamina cost, no more than Ninjutsu knowledge stat x 1. Why Nin x 1?

When making a jutsu always assume that Nin KS is 100 (since that's the usual cap) to orient yourself. This will mean that the jutsu will normally have 100 power at most. Doesn't sound much since a basic action (with the Physical stats at max) would do around 250 attack or defense for a lot less BP and stamina. That is where the effects come in. Giving a jutsu effects will give it an edge that can't be emulated by basic actions or taijutsus or genjutsus.

For example take this jutsu:

Spoiler:

Its effect "Regenerating attack and defense (100%)" means that if your opponent uses basic actions against it, like throw kunai at it or block it with his arms, the flames will just slip right through them unaffected, thus the jutsu will remain at full power. Furthermore, since this jutsu has both an attack and defense power you can use it to overwhelm the enemy's attacks then keep on going and attack the enemy itself (a simultaneous defense and attack). In an rp this is how it would look like:

Lets say the enemy is 10 meters away and threw 3 series of shuriken at me one after the other (all from the same spot, and he hasn't moved).
Round 1: atk p 112
Round 2: atk p 120
Round 3: atk p 102
My RT (reaction time) for the first round is 3 (distance gives me 2; enemy BP cost gives me 1. 2+1=3). SO what do I do? I use the Karyuudan on them (BP cost 2). The jutsu hits the first wave of kunai (100 VS 112). My jutsu is reduced to 0, enemy attack is reduced to 12, BUT my jutsu regenerates back to 100. Since the next wave came from the same direction (meaning its still within the jutsus area of effect) it too hits my jutsu (100 VS 120). Same thing happens with the 3rd wave. My jutsu regenerates again and (because my enemy is within 10m, and hasn't moved sideways or something) it attacks him with 100 power. Furthermore, because I (technically) used this jutsu during the defense phase and sacrificed 2 RT to cast is, it also reduces the enemies RT by 2.

So you see, the effects make a lot of difference. If you made the BP, Stamina cost, power ratio unfair, you'll have to add crappy effects. Its all about balance. All of the effects are listed below in the "KEY" spoiler. Use them wisely and if you can think of an appropriate effect then add it to the list.

Another thing you need to know is that there are 3 effects you must always assign to a jutsu. Its size, type and area of effect Narrow or Wide (Narrow means it attacks in a straight line or only a specific grid. Wide means it spreads like a cone and attacks the entire general area), all other effects are optional. These are important because they affect how they measure up against other ninjutsus. For example: a larger sized non-physical jutsu would gain a 25% attack boost if used against a smaller physical defense jutsu because it would simply swallow it up.

Each element tends to favor a certain type (Katon jutsus tend to be non-pysical, water tend to be semi-physical, Earth tend to be physical jutsu), however to prevent this from making a certain element become predictable and having an exploitable weakness, now and again you should add a jutsu with a different type, just so it can have all its basis covered. Same goes for size and area of effect. Every element should have large and small jutsus, narrow and wide, semi, non and just physical jutsu.

The 5 sizes are : Tiny, small, medium, large, huge. The first and last should be used more rarely than the other 3.

Anyway, back to the guidelines:
-C rank elemental ninjutsus should have 2~5 BP cost, 10~22 stm cost, Nin x 1~4. If using both attack and defense then their total shouldn't exceed Nin x 6.

-B rank elemental ninjutsus should have 4~5 BP cost, 19~27 stm cost, Nin x 2~5.

-A rank elemental ninjutsus should have 6~7 BP cost, 27+ stm cost, Nin x 6+.

-S rank...no guidelines here. anything can happen with these guys, just maintain the balance.

Guidelines about effects:
Regeneration and Overwhelming are so far the strongest effects. Shared power is a strong negative effect, use it to balance things out if you overdue it with the others. Jutsus with longer durations should not have high power.
Jutsus with high power rating should not have high regeneration.
Jutsus with more than Nin x 2 should not have Overwhelming.

Key:

Spoiler: