Randart generation question

[Chud]

This started as a "look at this!" post after coming across one of the more laughable randarts I've seen:



But that made me curious about what it was based on, so I looked at randart.log, and I don't understand how this was generated. It looks like the stats for AC and speed got their signs flipped along the way, and it's not clear to me from the log why that happened?

>>>>>>>>>>>>>>>>>>>>>>>>>> CREATING NEW ARTIFACT
Artifact 23: power = 178
Creating Pair of Leather Sandals
Assigned basic stats, AC bonus: 13
********** Evaluating for base item power ********
Artifact index is 23
the Pair of Leather Sandals of Quenon [1,+13]
Mult after extra might is 1
After multiplying power for might, total is 0
Adding 1 power for base AC value
Add 4 power for AC per unit weight, now 5
Add 13 power for to_ac of 13, total is 18
Add 3 power for ignoring acid, total is 21
Add 1 power for ignoring electricity, total is 22
Add 3 power for ignoring fire, total is 25
Add 1 power for ignoring cold, total is 26
FINAL POWER IS 26
Base item power 26
Cumulative frequency of ability 0 is: 0
Cumulative frequency of ability 1 is: 0
Cumulative frequency of ability 2 is: 0
Cumulative frequency of ability 3 is: 0
Cumulative frequency of ability 4 is: 0
Cumulative frequency of ability 5 is: 0
Cumulative frequency of ability 6 is: 0
Cumulative frequency of ability 7 is: 0
Cumulative frequency of ability 8 is: 7
Cumulative frequency of ability 9 is: 9
Cumulative frequency of ability 10 is: 10
Cumulative frequency of ability 11 is: 11
Cumulative frequency of ability 12 is: 12
Cumulative frequency of ability 13 is: 12
Cumulative frequency of ability 14 is: 12
Cumulative frequency of ability 15 is: 12
Cumulative frequency of ability 16 is: 12
Cumulative frequency of ability 17 is: 12
Cumulative frequency of ability 18 is: 12
Cumulative frequency of ability 19 is: 12
Cumulative frequency of ability 20 is: 12
Cumulative frequency of ability 21 is: 12
Cumulative frequency of ability 22 is: 56
Cumulative frequency of ability 23 is: 102
Cumulative frequency of ability 24 is: 148
Cumulative frequency of ability 25 is: 194
Cumulative frequency of ability 26 is: 217
Cumulative frequency of ability 27 is: 286
Cumulative frequency of ability 28 is: 309
Cumulative frequency of ability 29 is: 309
Cumulative frequency of ability 30 is: 309
Cumulative frequency of ability 31 is: 309
Cumulative frequency of ability 32 is: 309
Cumulative frequency of ability 33 is: 309
Cumulative frequency of ability 34 is: 309
Cumulative frequency of ability 35 is: 309
Cumulative frequency of ability 36 is: 309
Cumulative frequency of ability 37 is: 309
Cumulative frequency of ability 38 is: 309
Cumulative frequency of ability 39 is: 309
Cumulative frequency of ability 40 is: 309
Cumulative frequency of ability 41 is: 309
Cumulative frequency of ability 42 is: 309
Cumulative frequency of ability 43 is: 309
Cumulative frequency of ability 44 is: 309
Cumulative frequency of ability 45 is: 309
Cumulative frequency of ability 46 is: 309
Cumulative frequency of ability 47 is: 309
Cumulative frequency of ability 48 is: 309
Cumulative frequency of ability 49 is: 309
Cumulative frequency of ability 50 is: 459
Cumulative frequency of ability 51 is: 487
Cumulative frequency of ability 52 is: 495
Cumulative frequency of ability 53 is: 502
Cumulative frequency of ability 54 is: 509
Cumulative frequency of ability 55 is: 528
Cumulative frequency of ability 56 is: 544
Cumulative frequency of ability 57 is: 581
Cumulative frequency of ability 58 is: 589
Cumulative frequency of ability 59 is: 599
Cumulative frequency of ability 60 is: 625
Cumulative frequency of ability 61 is: 635
Cumulative frequency of ability 62 is: 640
Cumulative frequency of ability 63 is: 657
Cumulative frequency of ability 64 is: 675
Cumulative frequency of ability 65 is: 776
Cumulative frequency of ability 66 is: 790
Cumulative frequency of ability 67 is: 814
Cumulative frequency of ability 68 is: 836
Cumulative frequency of ability 69 is: 865
Cumulative frequency of ability 70 is: 874
Cumulative frequency of ability 71 is: 885
Cumulative frequency of ability 72 is: 892
Cumulative frequency of ability 73 is: 899
Cumulative frequency of ability 74 is: 909
Cumulative frequency of ability 75 is: 921
Cumulative frequency of ability 76 is: 931
Cumulative frequency of ability 77 is: 944
Cumulative frequency of ability 78 is: 949
Cumulative frequency of ability 79 is: 954
Cumulative frequency of ability 80 is: 1020
Cumulative frequency of ability 81 is: 1023
Cumulative frequency of ability 82 is: 1024
Cumulative frequency of ability 83 is: 1024
Cumulative frequency of ability 84 is: 1024
Cumulative frequency of ability 85 is: 1024
Cumulative frequency of ability 86 is: 1026
Cumulative frequency of ability 87 is: 1026
Cumulative frequency of ability 88 is: 1026
Cumulative frequency of ability 89 is: 1026
Cumulative frequency of ability 90 is: 1026
Cumulative frequency of ability 91 is: 1026
Cumulative frequency of ability 92 is: 1026
Cumulative frequency of ability 93 is: 1026
Supercharging speed for this item!  (New speed bonus is 5)
********** Evaluating result of supercharge ********
Artifact index is 23
the Pair of Leather Sandals of Quenon [1,+13] <+5>
Mult after extra might is 1
After multiplying power for might, total is 0
Adding 1 power for base AC value
Add 4 power for AC per unit weight, now 5
Add 13 power for to_ac of 13, total is 18
Add 100 power for 5 speed, total is 118
Add 3 power for ignoring acid, total is 121
Add 1 power for ignoring electricity, total is 122
Add 3 power for ignoring fire, total is 125
Add 1 power for ignoring cold, total is 126
FINAL POWER IS 126
Ability chosen was number: 26
Adding ability: trap immunity
********** Evaluating artifact attempt ********
Artifact index is 23
the Pair of Leather Sandals of Quenon [1,+13] <+5>
Mult after extra might is 1
After multiplying power for might, total is 0
Adding 1 power for base AC value
Add 4 power for AC per unit weight, now 5
Add 13 power for to_ac of 13, total is 18
Add 100 power for 5 speed, total is 118
Add 10 power for trap immunity, total is 128
Add 3 power for ignoring acid, total is 131
Add 1 power for ignoring electricity, total is 132
Add 3 power for ignoring fire, total is 135
Add 1 power for ignoring cold, total is 136
FINAL POWER IS 136
Ability chosen was number: 50
Adding ability: constitution (+4)
********** Evaluating artifact attempt ********
Artifact index is 23
the Pair of Leather Sandals of Quenon [1,-13] <+4, +5> {cursed}
Mult after extra might is 1
After multiplying power for might, total is 0
Adding 1 power for base AC value
Add -6 power for AC per unit weight, now -5
Add -13 power for to_ac of -13, total is -18
Add 48 power for 4 constitution, total is 30
Add 100 power for 5 speed, total is 130
Add 6 power for modifier total of 90, total is 136
Add -5 power for experience drain, total is 131
Add 10 power for trap immunity, total is 141
Add 3 power for ignoring acid, total is 144
Add 1 power for ignoring electricity, total is 145
Add 3 power for ignoring fire, total is 148
Add 1 power for ignoring cold, total is 149
Calculating impair hitpoint recovery curse power...
Mult after extra might is 1
After multiplying power for might, total is 0
Add -8 power for impaired hitpoint recovery, total is -8
FINAL POWER IS -8
Adjust for strength of curse, -9 for impair hitpoint recovery curse power
Total of -9 power added for curses, total is 140
FINAL POWER IS 140
Ability chosen was number: 80
Adding activation effect 94
********** Evaluating artifact attempt ********
Artifact index is 23
the Pair of Leather Sandals of Quenon [1,-13] <+4, -5> {cursed}
Mult after extra might is 1
After multiplying power for might, total is 0
Adding 1 power for base AC value
Add -6 power for AC per unit weight, now -5
Add -13 power for to_ac of -13, total is -18
Add 48 power for 4 constitution, total is 30
Add -100 power for -5 speed, total is -70
Add -20 power for teleportation ban, total is -90
Add -5 power for experience drain, total is -95
Add 10 power for trap immunity, total is -85
Add 3 power for ignoring acid, total is -82
Add 1 power for ignoring electricity, total is -81
Add 3 power for ignoring fire, total is -78
Add 1 power for ignoring cold, total is -77
Add 8 power for item activation, total is -69
Calculating impair hitpoint recovery curse power...
Mult after extra might is 1
After multiplying power for might, total is 0
Add -8 power for impaired hitpoint recovery, total is -8
FINAL POWER IS -8
Adjust for strength of curse, -9 for impair hitpoint recovery curse power
Calculating siren curse power...
Mult after extra might is 1
After multiplying power for might, total is 0
FINAL POWER IS 0
Adjust for strength of curse, 0 for siren curse power
Total of -9 power added for curses, total is -78
FINAL POWER IS -78
New depths are min 18, max 46
Power-based alloc_prob is 32
<<<<<<<<<<<<<<<<<<<<<<<<<< ARTIFACT COMPLETED
Number of tries for artifact 23 was: 2

[Chud]

Sorry - to add, this is nightly build version 4.2.4-162-g330f952cf

[backwardsEric]

There's a chance that a random artifact gets a load of undesirable properties (if one is looking at obj-randart.c, look for hurt_me or make_bad). That particular artifact was fairly unlucky, a 1/392 chance, for the properties it picked up from that. The addition of those undesirable properties isn't logged (probably should be) and doesn't affect the power shown in the log.

This isn't something that's changed recently: the last change in the make_bad() routine was three years ago and most of the logic there predates the 4.2.* releases.

[Chud]

That makes sense - thanks. It was the lack of logging when bad things are added that confused me.

[Sky]

randarts are no longer based on the standart list, they are generated completely anew.