[GW2] Precursor Gambling

I feel for this guy.

On its own, a random number generator is not fair, moral, or kind. It is just random.

Which is probably why RNG makes for such terrible gameplay.

Much of GW2's endgame* focuses on the hunt for cosmetic improvements - legendary items with no stat bonus, but unique skins / animations. To keep these items rare, the precursor weapons to legendary items are low-chance results from mystic forge gambling.

Using mystic forge gambling to obtain precursors is a controversial mechanic (at best). The forums drama has been fairly intense. Fortunately, Arena Net heard the complaints and has some (unfortunately vague) plans to make obtaining a precursor both fun and legendary.
UPDATE [11/15]: So far, they haven't provided an alternative path to get a precursor, just 'slightly increased the drop rate'.  Booo.

But before the system is thrown into the dustbin of poor implementation, I wanted to take a moment and examine one reason why using RNG to gate progression is a terrible idea: the distribution of cost.

Luck and Cost

Some players get a precursor on their attempt... while others throw thousands of items into the forge with no result. I want to visualize that difference.

From the last post, I have a reasonable expectation that four rare items have a 20% chance of returning an exotic. I'm going to guess that this exotic has either a 1%, 1.3%, 2% or 4% chance of being a precursor. And I'll check three different ways of getting precursors:

• Plan 1: crafting rares, selling all exotic outcomes until a precursor is found
• Plan 2: crafting rares, reforging all non-precursor exotics
• Plan 3: crafting exotics, reforging all non-precursor exotics

Under these conditions, here is the estimated (average) cost of mystic forge gambling (in gold), using greatswords as a baseline, broken down the the chance for an exotic to be the precursor.**

1% 1.3% 2% 4%
Plan 1: 210.83 150.80 101.67 51.83
Plan 2: 278.88 210.91 141.47 71.36 
Plan 3: 693.11 524.63 346.16 174.87

These averages are (generally) reasonable. Under these assumptions, even at a 1% chance, a precursor is around a 200g investment, making it expensive, but attainable.

There are two things to note.

1. Crafting exotics to obtain a precursor is three times as expensive as crafting rares. This doesn't necessarily mean that using exotics to obtain precursors is a bad idea. They might have 3x the chance of yielding precursors - its just that nobody has the data to find out. Fortunately, in terms of puzzling out why luck is a bad way to gate progression, this doesn't matter, so I'll focus on plan 1 & 2 from this point on.
2. Given the current price of precursors... either the precursors are much rarer than I've assumed, or using the mystic forge may be profitable even at current prices.***

Luck and Extreme Outcomes

Average cost isn't the issue. Its the distribution of cost that is the problem.

And that is where luck hurts players.

Here, I've simulated the results of 5000 players using plan 1 to obtain a precursor from the mystic forge, varying the chance that an exotic is a precursor. I've plotted how much the luckiest 10% of players pay for a precursor by gambling, the unluckiest 10%, and two measures of the average player (mean and median).

As precursors become harder to obtain (moving to the left), the average cost of creating a precursor for the unluckiest 10% of players grows exponentially. For example, if an exotic has a 1% chance to be a precursor from the mystic forge, the unluckiest 10% spend an average of just over 800 gold to get a precursor, compared to around 200g for the average player.

And that is the problem with RNG: extreme outcomes.

Extremes are great if you're lucky, but horrible for the person throwing gold away.

A simple fix would be to institute a progressively increasing drop chance once a threshold has been exceeded. Great way to fix the discouraging luck issue.

Legendary design

There are better ways to design legendary journeys.

Both Shadowmourne and the Fangs of the Father questlines were fun, and helped add to the status of the item forged. Shadowmourne's components: reforged weapon of the biggest evil in the world, hardened with the pure blood of an old god, drenched in the souls of the enemy, and decorated with fragments of the throne of evil.

Randomly throwing weapons at a genie just can't compete with that. (And the player-invented lore behind legendaries is a reflection of that.)

The problem with RNG is that players don't earn the item. Which cheapens it. And it cheapens the journey. Because there is no journey, just a slot machine. Imagine Arthur winning Excalibur at a casino. Not epic.

It isn't fun from moment to moment. Its preparing to have fun.



* Stuff-to-do at 80.
** The choice of greatswords here doesn't shape the cost much - while the TP cost of precursors varies wildly, most weapons have approximately the same crafting cost. I'm also assuming that exotics are sold to market in Plan 1 for 1g.
*** Of course, if they're rarer, then some of the cheaper precursors are tremendous losses.