Why is magic item pricing exponential instead of linear?

[CRGreathouse]

While I agree with the majority on the reasoning, I have to point out that the pricing isn't exponential at all -- it's quadratic, which is much 'slower' in the long run.

Exponential might be 2000 (+1), 4000 (+2), 8000 (+3), 16 000 (+4), 32 000 (+5), 64 000 (+6), 128 000 (+7), 256 000 (+8), 512 000 (+9), 1 024 000 (+10), ...

 

[dinsdale]

While I agree with the majority on the reasoning, I have to point out that the pricing isn't exponential at all -- it's quadratic, which is much 'slower' in the long run.

Exponential might be 2000 (+1), 4000 (+2), 8000 (+3), 16 000 (+4), 32 000 (+5), 64 000 (+6), 128 000 (+7), 256 000 (+8), 512 000 (+9), 1 024 000 (+10), ...

You are correct to point out that the current system is quadratic (2*x^2, where x = weapon plus, to be precise). However, whether or not it is slower or faster than an exponential progression is going to depend a lot on what the exact equation is...

2000^x and 2000*(1^x) are both exponential and start with 2000 at +1, but the first will be at 4 million by +2, while the second is completely flat.

 

[Scion]

For the same reason it's faster to go from 0-60mph than it is to go from 60-120mph.

eww.. you cant say things like this! It is like stabbing a needle in my eye

Effectively that is untrue. Until you toss in things like drag and a few other factors..lol

Otherwise though, I think that mainly they increase as they do in order to get other parts of the priceing scheme set up like they want. Along with having the wealth chart increase as it does.

'Bigger and better' items are much more cost prohibitive. That way no character can have more than a few of them at most levels. But they can still have lots of little items. To reflect this the higher up ones must be much, much more expensive.

Effectively they are priced thusly to reflect how they wanted the system to appear in the final equation

 

[CRGreathouse]

You are correct to point out that the current system is quadratic (2*x^2, where x = weapon plus, to be precise). However, whether or not it is slower or faster than an exponential progression is going to depend a lot on what the exact equation is...

That's why I quoted 'slower'. Formally:
a>0, b>1 --> a*b^x > 2*x^2 for all x greater than some constant x_0.

The reason I tend to prefer exponential costs is that it can reduce the initial x4 in prices (2000 gp --> 8000 gp), which is a little steep IMO, without reducing costs in the long run.

 

[Flyspeck23]

nine +1 throwing daggers is better than a single +3 throwing dagger. But I guess that isn't exactly where you were going with it.

I guess you're right.

 

[Elder-Basilisk]

In terms of damage per round, there's already an exponential effect to enhancement bonusses for weapons and strength increases (the easiest effects to analyze).

A character who hits 50% of the time for 5 points of damage deals an average of 2.5 points of damage per round not counting criticals (lets assume he's fighting a zombie).

Give that character a +1 handaxe instead of his ordinary handaxe and now he's hitting 55% of the time for 6 points of damage. That's an average of 3.3 points of damage per round.

Make it a +2 handaxe and that's 60% of the time for 7 points of damage. 4.2 points of damage per round.

+3 handaxe? 65% for 8 points. An average of 5.2
+4 70% and 9 points for an average of 6.3
+5 75% and 10 points for an average of 7.5 points of damage/round

As you can see, each increas in enhancement bonus yields a slightly higher increase in average damage/round than the last. Going from +4 to +5 is more significant than going from +1 to +2

Of course, that's not the whole story either. Feats like power attack and cleave can serve to magnify the exponential effect of the power.

Most other items have similar effects. If your midlevel character wants to reduce the damage you take in a fight, going from AC 20 to 30 is far more significant than going from AC 10 to 20. If your 12th level wizard with a 17 int takes his headband of intellect from +4 to +6, that's more significant than going from +2 to +4. (Not only do his DCs increase, but he also gets better bonus spells--2nd and 6th level instead of 1st and 5th).

What may be a more important reason is that it probably models the rarity that the game designers (and many DMs) want in their worlds. +1 weapons aren't exactly common but few DMs think that they're legendary items and there's only one of them in any given kingdom. +2 and +3 swords are a lot rarer but you still want to be able to put a fair number of them throughout the kingdom. When you get to +5 swords though, you're talking about something very rare and special. And a +10 (equivalent) sword--maybe there's only a few of them in the world (of course, epic changes the scale of things somewhat but that's neither here nor there). The point is that the exponential price increase fits increase in rarity fairly well.

 

[MarauderX]

In fact, it has nothing at all to do with supply and demand. Though such economic factors can influenece the market value of an item, the cost to create a magical item is simply not affected by such factors (nor should it be). It costs a Wizard in a worn torn land with a high demand for magical arms the exact same amount of gold and experience to make a +1 sword as it does another wizard in a land where such items are not needed or wanted by anyone. How much he may charge his customers to purchase the weapon, however, is a different matter entirely.

Such is your campaign, if you wish it to be by the exact rules. I make adjustments according to location, and I don't use the item creation rules in 3.0 or 3.5. As for Greyhawk, explain away the costs however you wish, it seems everything would apply.

 

[Scion]

Such is your campaign, if you wish it to be by the exact rules.

Of course, this is the rules forum

 

[MarauderX]

Of course, this is the rules forum

Oh yeah... keep forgetting I'm not a DM Overlord in public.

<slap on wrist> Must not rule 0 in the rules forum...