Spellcasting failure rate

[Frog Dragon]

So. I was checking the Thoughts on Magic thread and there was some great suggestions. As I read it, it became obvious what needed to be done to make the spellcaster own a little less. So here we go. Spellcasting Failure Rate. If you have suggestions on how to improve it please write them.

Spellcasting failure rate
When you cast a spell something may go avry. The magics might not work as you intended. You might fail to speak the right words or gesture right. And if that happens. Your spell might just blast on you.

When casting a spell make this check before applying any effects
Half you caster level (minimum 1) + the relevant ability modifier to cast the spell against this 6+ spell level. If this check fails, your spell fizzles. On first and second level spells there are modifiers representing the relative ease of casting these spells. You cannot fail cantrips.
If you roll a natural 1 the make the check again but double the DC. If this check succeeds the spell is lost, but no components or spell slots are lost
If it fails the spell that just went out of control deals 1d4 damge per spell level and the components and the spell slot are lost.

{table=head]Spell Level | DC
1. | 5
2. | 7
3. | 9
4. | 10
5. | 11
6. | 12
7. | 13
8. | 14
9. | 15[/table]

So post your thoughts on this. How could I improve it. I was aiming for a 10% chance to fail your best spell.

[MeklorIlavator]

Quite Frankly, I don't think this works. At early levels it would be present, but later on the checks become trivial except for the 5% failure rate. I mean, by level 13(7th level spells) I have a Mad Character who has a +5 to Int, and he's not even really focusing on it. If I wanted to focus I could easily get it up to +6, which means he only fails on a 1. Lets not even get started on the really high levels. Plus, the 5% failure rate is likely too much in the current magic system.

[Frog Dragon]

Yeah but it's not meant to be big. And the half caster level+ Int mod vs DC matters more in the stage where the DC is doubled, failure and spell blows up on your face and that's what I was aiming for. Generally a higher risk to cast higher level spells. And anyway. Decently built wizards will not be in that bad a position because most of the time especially with lower level spells the spell just disappears, but leaves,you, your spell slots and you materials intact. And now that I think about it 10% might be too much especially when your spell can blow up on your face. I was aiming to take away a bit of the reliability of spellcasting. It still succeeds most of the time. And generally casters need to be weakened.

Lets say lvl 15 wizard casts an lvl 8 spell against a fighter of the same level. It's dominate monster so it's a will save. Now the Fighter has a base will save of +4 + wis mod. Lets say its +1 because Wis isn't a high priority for fighters. Then he has an item which picks it up by +6. Okay He has +11 Now lets see the wizzy. He most likely has at least 20 nat int and headband of int +6. Equals int mod of +8
with the save 26. What do we see. The fighter is screwed and most fighters don't even have that kind of boosting items meaning he's even more screwed. This doesn't mitigate that all so much, but what it does is bring the wizard on it's toes a bit because the spell may do more harm than good even when the chance is small.

[RS14]

Just make it a caster level check. Making it dependent on the casting stat just hurts gishes and doesn't hurt full spellcasters at all. If anything, it increases the demand for a caster to pump his casting stat to absurd levels, and I don't like that.

Also, this will not be convenient to use unless the DCs can be calculated by some convenient formula.

Finally, particularly at low levels, it would just suck to lose your only L1 spell of the day to a natural 1. I can see doing this -- even making it much more difficult -- but only in a different system where casting was unlimited or near unlimited per day.

[Frog Dragon]

Hmm. I need to redo the table then. BTW it actually has a formula to calculate DC is 6+ spell level with a -2 to levels 1 and -1 to level 2 against half caster level (minimum 1) + Relevat Casting Stat Mod

[The Minx]

You forgot about cantrips.

[Frog Dragon]

Read the first post. I didn't forget about them, I just decided they are not powerful enough to have a failure chance. I might do the same for lvl 1 spells.

[Rebonack]

It makes low level casting worse and really doesn't do anything to fix casting at higher levels where it gets really abusive. Eehh... I don't think a failure chance is really the way to go here.

Glad to see people are thinking about this, though.

[Kesnit]

Playing with (semi-)real numbers...

When casting a spell make this check before applying any effects
Half you caster level (minimum 1) + the relevant ability modifier to cast the spell against this 6+ spell level. If this check fails, your spell fizzles. On first and second level spells there are modifiers representing the relative ease of casting these spells. You cannot fail cantrips.

{table=head]Spell Level | DC
1. | 5
2. | 7
3. | 9
4. | 10
5. | 11
6. | 12
7. | 13
8. | 14
9. | 15[/table]

LVL 1
INT 16 (+3)
Casting a LVL 1 spell.
CL/2 = 1
INT mod = 3
Sum = 4.
As long as you don't roll a 1, you succeed.

LVL 4
INT 18 (+1 at LVL 4, Headband of INT +1)
Casting a 2nd LVL spell
CL/2 = 2
INT Mod +4
Sum = 5
You succeed 90% of the time. (Roll 3-20)

LVL 12
INT 23 (Headband of INT +4)
Casting a 6th level spell
CL/2 = 6
INT Mod +6
Sum = 12
You only fail on a 1.

LVL 15
INT 23 (Headband of INT +4)
Casting an 8th level spell
CL/2 = 7
INT Mod = +6
Sum = 13
Only fail on a 1.

LVL 17
INT 24/26 (Headband of INT +4, though +6 would be reasonable)
Casting a 9th level spell
CL/2 = 8
INT Mod = +6/+8
Sum = 14/16
Only fail on a 1

LVL 20
INT 27 (Headband of INT +6)
Casting a 9th level spell
CL/2 = 10
INT Mod = +8
Sum = 18
Only fail on a 1.


The idea is good, but the DCs are too low, if the idea is to have the caster actually have a real risk of failure. (5% isn't much of a risk.)

[The Minx]

Read the first post. I didn't forget about them, I just decided they are not powerful enough to have a failure chance. I might do the same for lvl 1 spells.

Ugh, sorry. That's what I get for skimming the post.

The idea is interesting, though the super spell-caster is still super, while the low-level spell-caster is still a bit of a loser. Perhaps you should have the DC for the high level spells rise more steeply than the caster level?

I think some kind of cost system might work better.

[Frog Dragon]

I don't believe in cost systems. I am a guy who is trying to build replacement for all XP costs.
Here's another shot
Caster level check vs DC = Spell Level x 2,5. Round down
Cantrips still unfailable
The same DC double against your caster level

{table=head]Spell Level | DC
1. | 2
2. | 5
3. | 7
4. | 10
5. | 12
6. | 15
7. | 17
8. | 20
9. | 22[/table]

Better?

[The Minx]

I don't believe in cost systems. I am a guy who is trying to build replacement for all XP costs.

Then we do not see eye to eye, since more XP costs are a tool I use a lot.

Here's another shot
Caster level check vs DC = 2 + Spell Level x 2,5. Round down

{table=head]Spell Level | DC
1. | 4
2. | 7
3. | 9
4. | 12
5. | 14
6. | 17
7. | 19
8. | 23
9. | 25[/table]

Better?

So, the 17th level caster has a 35% failure rate for the 9th level spell, and the 20th level caster needs a 20% failure rate. The first level caster has a 10% failure rate with his first level spell. Yes, this is a lot better. I don't know whether it will be enough to balance casters, though.

[Kesnit]

Here's another shot
Caster level check vs DC = Spell Level x 2,5. Round down
Cantrips still unfailable
The same DC double against your caster level

{table=head]Spell Level | DC
1. | 2
2. | 5
3. | 7
4. | 10
5. | 12
6. | 15
7. | 17
8. | 20
9. | 22[/table]

Better?

CL 1
Casting a LVL 1 spell.
As long as you don't roll a 1, you succeed. (95% success)

CL 3
Casting a 2nd LVL spell
Don't roll a 1. (95% success)

CL 5
Casting a 3rd LVL spell
Don't roll a 1. (95% success)

CL 7
Casting a 4th LVL spell
Fail 1-2. (90% success)

CL 9
Casting a 5th LVL spell
Fail 1-2. (90% success)

CL 11
Casting a 6th level spell
You fail on a roll of 1-3. (85% success)

CL 13
Casting a 7th LVL spell
You fail on a roll of 1-3. (85% success)

CL 15
Casting an 8th level spell
Fail 1-4. (80% success)

CL 17
Casting a 9th level spell
Fail 1-4. (80% success)

CL 20
Only fail on a 1. (95% success)

Caster levels (except 20) are the lowest level you could cast a spell of that level.

It scales better, and as you gain levels, your chance of failing a given spell level decreases until you have a 5% chance of failure of any level. I'm just not sure if 5% is enough. After all, you are telling the laws of physics to sit down and shut up.

[Frog Dragon]

Consider the fact that if you fail your spell might blow up in your face!

And it's double DC making it more hard

Also note that this helps bards and other classes with stunted spellcasting. And I think that's good because full casters are at an advantage against half/secondary casters.

{table=head]Spell Level | DC | Second DC
1. | 2 | 4
2. | 5 | 10
3. | 7 | 14
4. | 10 | 20
5. | 12 | 24
6. | 15 | 30
7. | 17 | 34
8. | 20 | 40
9. | 22 | 44[/table]

The second DC is on the high level side only winnable by nat 20. It represents the innate difficulty of bringing such powerful magics back under control after failing once. Basically if you fail the first check then make another check with the Second DC.
If you succeed you do not lose materials, spell slots or XP. You don't lose a thing except for the action you wwould use to cast the spell.
If you fail you cannot get the spell back under control quickly enough and it basically blows up on your face. You lose the spell slot as if you had cast the spell normally, you also lose any materials and other things that would be expended if the spell had succeeded. Then you take 1d4 damage per spell level of the spell you failed.

[Kesnit]

This one occurred to me last night.

When you cast a spell, roll a d20. If the roll is greater than or equal to the spell level, the spell goes off as intended. (Cantrips always succeed. A 1 autofails.) If the roll is less than the level, roll again. If this roll is greater than or equal to the spell level, nothing happens. (The spell doesn't go off, but you don't lose the slot or the materials/gold/XP.) If the second roll is less than the level, the spell backfires. Damage spells attack the caster. Summoned creatures attack the caster and his/her party. Buff spells affect a random enemy.

Spoiler

Show

1st level spell:
95% chance of success
.25% of backfire

2nd level spell:
95% chance of success
.25% chance of backfire

3rd level spell:
90% chance of success
1% chance of backfire

4th level spell:
85% chance of success
2.25% chance of backfire

5th level spell:
80% chance of success
4% chance of backfire

6th level spell:
75% chance of success
6.25% chance of backfire

7th level spell:
70% chance of success
9% chance of backfire

8th level spell:
65% chance of success
12.25% chance of backfire

9th level spell:
60% chance of success
16% chance of backfire

[Akennedy]

I made something a little while ago that lost the interest of the public eye, here ya are.

http://www.giantitp.com/forums/showthread.php?t=96575

See "New Exciting post"

I'd link it, but I'm jealous a less refined system has received more attention than mine