summaryrefslogtreecommitdiffstats
path: root/crawl-ref/docs/develop/levels/syntax.txt
blob: c755b46b03b69c6be2e67ccf2c2dfabe58adb760 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
-----------------------------------------------
How to make levels for Dungeon Crawl Stone Soup
-----------------------------------------------

Part II:      SYNTAX
              ======

Contents:  G. Glyphs
           H. Header information

This document contains the syntax needed for making maps and vaults. It
does not say anything about principles of vault making; for this, see
introduction.txt. For more technical aspects, including tests, lua and
portal vaults, refer to advanced.txt. For Triggerables, please see triggerables.txt.

G.   Glyphs
===========

Terrain
-------
 x - rock wall                                            (DNGN_ROCK_WALL)
 X - permanent rock wall  - always undiggable        (DNGN_PERMAROCK_WALL)
 c - stone wall - only affected by Shatter               (DNGN_STONE_WALL)
 m - clear rock wall                                (DNGN_CLEAR_ROCK_WALL)
 n - clear stone wall - only affected by Shatter   (DNGN_CLEAR_STONE_WALL)
 o - clear permanent rock wall - always undiggable (DNGN_CLEAR_PERMAROCK_WALL)
 v - metal wall - grounds electricity                    (DNGN_METAL_WALL)
 b - crystal wall - reflects cold and fire       (DNGN_GREEN_CRYSTAL_WALL)
 a - wax wall - can melt                                   (DNGN_WAX_WALL)
 t - trees - a single square doesn't block LOS                (DNGN_TREES)

 . - floor                                                    (DNGN_FLOOR)
 + - closed door                                        (DNGN_CLOSED_DOOR)
 = - secret door                                        (DNGN_SECRET_DOOR)

 W - shallow water
 w - deep water - can be randomly turned into shallow water by the
     level-builder; you can prevent this conversion with the no_pool_fixup TAG.
     Also, water may automatically receive water creatures! For entry
     vaults, avoid this with the no_monster_gen TAG or KMASK.
 l - lava - again, use the no_monster_gen TAG or KMASK for entry vaults!

Features
--------
 @ - entry point - must be on outside edge. If you use ORIENT: float, and do
     not use any @, the dungeon builder will connect at least one floorspace on
     the edge of your map to the rest of the level; if there is no floorspace
     on the edge of your map, it will be isolated.
 }{ - Stone stairs - You must be able to reach these from each other. The
      { upstair is also the stair on which the player will enter the
      dungeon for entry vaults.
 )( - Stone stairs, set 2.
 ][ - Stone stairs, set 3.

 >< - escape hatches - you can leave the level by these but will usually
      not land on stairs/hatches

 I - orcish idol (does nothing)

 ^ - random trap.
 ~ - random trap suitable for the branch and depth the map is being used.

 A - Vestibule gateway (opened by Horn).
 B - Altar. These are assigned specific types (e.g. of Zin etc) in dungeon.cc,
     in order.
 C - Random Altar.

 G - Granite statue (does nothing) - you can see through but not walk through.
     Also, sight-based effects like smiting work past granite statues, as does
     apportation.

     NOTE: F used to put down a granite Statue most of the time but occasionally
     Orange or Silver or Ice statues (1 in 100). You can reproduce this by using
     F on the map together with
     SUBST:   F = G:100 F:1
     KMONS:   F = orange crystal statue / silver statue / ice statue

 T - Water fountain
 U - Magic fountain
 V - Permanently dry fountain
 Y - Blood fountain (use sparingly!)

Items
-----
 $ - gold
 % - normal item
 * - higher level item (good)
 | - acquirement-level item (almost guaranteed excellent)
 O - place an appropriate rune here. For portal vaults, place the portal here.
 d-k - item array item. See section below on ITEM: arrays for more info.

NOTE: The P (place a rune here with 1/3 chance) and R (place a honeycomb with
      2/3 chance or else a royal jelly) symbols have been removed. You can
      produce the desired behaviour using
      SUBST: P = O..
      KITEM: R = w:2 honeycomb / w:1 royal jelly

Monsters
--------
 0 - normal monster
 9 - +5 depth monster
 8 - (+2) * 2 depth monster (aargh!). Can get golden dragons and titans
     this way.[*]
 1-7 - monster array monster. See section below on MONS: arrays for more
     information

[*]  (using '0', '9', and '8' in portal vaults will use monsters from the
      level that the portal was entered from, unless a random monster list
      has been set)

H.   Header information
=======================

(All declarations apart from NAME: are translated to Lua function calls
behind the scenes. See the Lua reference for more information.)

Try to respect line lengths of 80 characters. Should some line exceed that
(which is quite possible, especially for ITEM and MONS lines), you can use
the \ symbol to break a line. You can break a line anywhere, with the
exception of comma-separated lists, where you cannot start a new line with
a comma. See the end of this section for examples.

NAME:     a_string
          Each map must have a unique name. Underscores and digits are ok.

ORIENT:   (float |encompass | north | northwest | ... | southeast)

          Some kind of ORIENT: line is mandatory for vaults; skipping
          ORIENT: makes your map a minivault. As a rule of thumb, if
          you're writing a small random map, skip the ORIENT: line and
          make it a minivault.

          * "float": The dungeon builder puts your vault wherever it wants to.
          * "some_direction": The vault lies along that side of the map:
              xxxxxxxxxx       xxxxxxxxxxxxx
              xORIENT:Nx       xORIENT:NW|..
              x.VAULT..x       x.VAULT...|..
              x--------x       x---------|..
              xrest....x       xrest........
              x...of...x       x.....of.....
              x...levelx       x.......level

          ORIENT: float vaults give a lot of flexibility to the dungeon
          generator; float should generally be preferred to other ORIENT:
          settings for new vaults.

DEPTH:    For random vaults, branch entry vaults, and minivaults, this
          specifies the range of levels where the vault may be placed
          in the dungeon. E.g.

            DEPTH: 7-20

          DEPTH: does not force a map to be placed in a particular place; it
          applies only when the dungeon builder is looking for a random vault
          or minivault, so you can control at what depths your vault gets
          placed.

          A simple DEPTH: declaration that does not specify a branch
          applies to all branches. A map declared with depth 7-20 could
          be used in the Lair, for instance. (Lair:1 will be treated as
          a depth of 12 if the Lair entrance is on D:11.)

          You can constrain a map by branch:

            DEPTH: Lair:3-6

          (Anywhere between levels 3-6 of the Lair, inclusive.)

          You can apply multiple constraints in one DEPTH line,
          comma-separated:

            DEPTH: 7-20, !12-14

          (Anywhere in the dungeon between depths 7-20, but not on levels
          12-14.)

            DEPTH: 7-20, !Orc

          (Anywhere in the dungeon between depths 7-20, but never in the Orcish
          Mines.)

            DEPTH: Lair:*

          (Anywhere in the Lair. Can also be expressed as "DEPTH: Lair".)

          Maps that do not specify a DEPTH: attribute will inherit their depth
          constraints from the closest preceding default-depth: line. If there
          is no preceding default-depth directive in the .des file, the map will
          have no DEPTH: constraint. Note that maps without a DEPTH: constraint
          cannot be selected as random vaults or minivaults.

CHANCE:   <priority>:<roll> or <roll>

          CHANCE allows you to control the probability that your map
          is used on any given level with an absolute roll.

          There are two ways to specify the CHANCE roll:

          CHANCE: 500
          or
          CHANCE: 5%

          If specified as a raw number, the chance of selecting the
          vault is <number> in 10000. If specified as a percentage,
          the chance of selecting the vault is <perc> * 100 in 10000.
          Note that CHANCE accepts only integers, no fractions or
          decimals.

          For any map with alternatives, a CHANCE influences how
          likely the map is to be picked instead of the alternatives.
          If a map has a CHANCE, Crawl will roll a random number in
          the range 1-10000, and select the map if the CHANCE is >=
          the rolled random number.

          If there are multiple alternative maps with CHANCE, they
          will be tested in an unspecified order; the first map that
          makes the CHANCE roll will be used. If you'd like to specify
          an order of testing CHANCEs, specify a CHANCE with a
          priority:

             CHANCE: 10 : 20%

          This specifies a CHANCE of 20%, with a priority of 10, which
          means this vault will be checked before any other vault with
          a lower priority (the default priority is 0).

          If no map with a CHANCE is picked, Crawl will select a map
          based on WEIGHT, ignoring vaults with a CHANCE set.

          Note that the Lua equivalent for CHANCE is a two-argument
          function:

          : chance(<priority>, <number>)

          These lines are all equivalent:
          CHANCE: 5%
          CHANCE: 500
          CHANCE: 0 : 5%
          CHANCE: 0 : 500
          : chance(0, 500)

          A common case when using CHANCE is to assign a CHANCE to a
          set of maps. For instance, if you have a set of portal vault
          entries, and you want one of the set to be used on 5% of all
          levels, you can do this:

          NAME: portal_a
          CHANCE: 50 : 5%
          TAGS: chance_portal_group
          ...

          NAME: portal_b
          CHANCE: 50 : 5%
          TAGS: chance_portal_group
          ...

          That is, if you have a set of maps that use CHANCE and are
          tagged chance_xxx, then one map of that set will be used
          when the chance is met.

WEIGHT:   (number with 10 being default)
          For entry vaults and any other vaults randomly picked from among
          a set, this type of line affects the likelihood of the given vault
          being picked in a given game. The default WEIGHT: is 10. The
          likelihood of a vault getting picked is:
          [vault's WEIGHT: / sum of all WEIGHT:s of vaults of that type]

PLACE:    Used to specify certain special levels. Existing special levels
          include most branch ends.
          The branches need to use the official abbreviations also used e.g. in
          the overmap (Ctrl-O): D, Temple, Orc, Elf, Lair, Swamp, Shoal, Slime,
          Snake, Hive, Vault, Blade, Crypt, Tomb, Hell, Dis, Geh, Coc, Tar, Zot.

          PLACE can also be used to specify arbitrary places, like D:3, which
          will force the map (or one of the maps with PLACE: D:3) to be picked
          when D:3 is generated.

          PLACE cannot be used to specify places in the Abyss, Pandemonium,
          or Labyrinths.

          PLACE can be used with random vaults and minivaults for testing them.

TAGS:     Tags go on a TAGS: line and are space-separated. You can have several
          TAGS: lines, or use \ for very long ones. Valid tags are:
          * "allow_dup": Vaults are normally used only once per game. If you
             have a vault that can be used more than once, use allow_dup to tell
             the dungeon builder that the vault can be reused.
          * "chance_FOO": Maps can be tagged chance_ with any unique suffix
             to indicate that if the map's CHANCE roll is made, one of the maps
             tagged chance_FOO should be picked.
          * "dummy": this tag indicates that the vault is a stub; if the dungeon
             builder picks a dummy vault, it pretends no vault was selected.
             Dummies are used to reduce the probability of other vaults at the
             same depth / place.
          * "entry": this tag MUST be there for a vault to be pickable as an
             entry vault.
          * "extra": requests that the dungeon builder treat this as
             an extra vault and try to immediately place another vault of the
             same type it was trying to place when it placed this vault.
             "extra" is good to use for things like labyrinth entries
             that should not affect the chance of other minivaults on the level.
             If you use "extra", you probably want to use one of the
             "luniq" tags as well if your map is tagged "allow_dup".
          * "generate_awake": Monsters placed (using MONS, KMONS) in this vault
             will be generated awake.
          * "patrolling": Monsters placed (using MONS, KMONS) in this vault
             will be generated with their starting position as patrol point.
             If not otherwise occupied (fighting, seeking) they will patrol
             the area.
          * "no_item_gen": Prevents random item generation in the vault.
             Items explicitly placed by the vault are not affected.
          * "mini_float": applicable only to minivaults, requests that
             the dungeon builder pick random exits from the minivault and
             connect it to the rest of the level, similar to the exit behaviour
             for floating vaults.
          * "no_monster_gen": Prevents random monster generation at the time of
             the vault's creation. Highly advised for entry vaults with a
             player-hostile geography, MUST-HAVE for those with water/lava.
             Can be applied only to particular symbols with KMASK.
          * "no_pool_fixup": prevents water squares next to land from being
             randomly converted from deep water (the default) to shallow.
          * "no_wall_fixup": In Dis, the Vaults and the Crypt a vault's
             rock walls will be changed to be the same as the wall type of
             the rest of the level.  If you don't want that to happen then
             use this tag.
          * "uniq_BAR": (uniq_ with any suffix) specifies that only one of
             the vaults with this tag can be used in a game.
          * "luniq": specifies that this vault can be used only once on a
             given level. "luniq" is only relevant when used with "allow_dup".
          * "luniq_BAR": (luniq_ with any suffix) specifies that only one
             of the vaults with this tag can be used on any given level.
             "luniq_BAR" is only relevant when used with "allow_dup".
          * "branch_entry" eg. "orc_entry", "lair_entry" etc.
             If chosen, these maps will contain the stairs for that branch.
             Use "O" to place the stairs. If a branch has very few entries,
             a dummy entry is advisable to make sure the player doesn't get
             bored of the same few entries recycled ad nauseam.
             Note: if any TAG argument contains an "entry", the vault will
                   be no longer eligible for random placement. (Currently,
                   this just affects your choice of BAR when using uniq_BAR.)
          * "mnoleg" or the name of some other pandemonium lord. This makes
             the map eligible for said pan lord's lair. See pan.des.
          * "minotaur" turns this into a labyrinth exit vault.
            "lab" turns this into an additional labyrinth flavour vault.
            See lab.des for examples and details.
          * "no_rotate":  Normally, the dungeon builder can, at its whim,
             rotate your vault. This flag tells it, "hey, don't do that to my
             vault!"
          * "no_hmirror": Like no_rotate, but for horizontal mirroring.
          * "no_vmirror": Like no_rotate, but for vertical mirroring.
          * "layout": Lua code that dungeon.cc uses for generating level
             layouts.  Do *NOT* use or mess with unless you know what
             you're doing.
          * "layout_foo": Indicates what sort of level layouts this vault is
             compatible with, for vaults that don't fit in with all layouts;
             the absence of this type of tags means it can go with any layout.
             Multiple layout_foo tags can be used if it can be used with
             multiple layouts.  Current values for "foo" are: rooms, city,
             open, caves, cross, shoals, swamp, labyrinth (though currently
             random vaults aren't placed in the last three).
          * "trowel_portal": This vault can be created by the Trowel card.
             This tag should be used exclusively for the generic (one tile)
             entries to portal vaults, like bazaars and labyrinths. Other
             portal vaults may be eligible for Trowel, too.
          * "no_dump": Don't dump out this vault's name in the list of
             vaults generated during the game.  Use this if the vault
             is predictable (like the Vault:8 and Slime:6 vaults) or
             are for weird internal uses (like the shoalhut vaults).

LFLAGS:   Persistent, changeable per-level flags which affect game behaviour
          (FLAGS just controls how the vault is placed); should only be used
          for vaults with ORIENT encompass or with PLACE. Causes a level's
          flags to be set when the level is first created. These flags can
          later be altered using Lua markers; for examples, look at the slime
          pit vault in lair.des, and the vaults in hell.des and elf.des.

          Valid flags are:
          * no_tele_control - prevents the player from using teleport control
          * not_mappable    - prevents the player from remembering where
                              they've been (like in the Abyss)
          * no_magic_map    - which prevents magic mapping from working.

BFLAGS:   Persistent, changeable per-*branch* flags which affect game
          behaviour; should only be used for vaults which go on the first
          level of a particular branch. These flags can later be altered
          using Lua markers; see the Tomb vaults in vaults.lua for an
          example.

          Valid flags are:
          * no_tele_control - prevents the player from using teleport control
          * not_mappable    - prevents the player from remembering where
                              they've been (like in the Abyss)
          * no_magic_map    - which prevents magic mapping from working.

LFLOORCOL: blue
          LFLOORCOL: allows you to set the floor colour for the level the
          vault appears in. Should only be used for bazaars and other
          portal vaults.

LROCKCOL: yellow
          LROCKCOL: allows you to set the colour of rock walls for the level
          the vault appears in. Should only be used for bazaars and other
          portal vaults.

LFLOORTILE: (tile name string, e.g. "floor_tomb")
          Like LFLOORCOL, this overrides the default floor tiles used for
          this level. If the tile specified has variations, those will be
          used automatically.

LROCKTILE: (tile name string, e.g. "wall_hive")
          Same as LFLOORTILE, but for rock walls.

ITEM:     (list of items, separated by comma)
          These are used to help place specified items at specific places
          within a vault. They create an array with up to 8 positions. What's
          in the first position in the array will be used when the dungeon
          builder sees a "d" in the vault definition, the second will be used
          for "e"s, etc. Positions are comma-separated; several ITEM: lines
          are possible as well. The following defines letters 'd' - 'g':
            ITEM: stone, ring mail, meat ration, ring of hunger

          Positions can contain multiple possibilities, one of which the
          builder will choose randomly. Separate such multiple possibilities
          using a slash. Note that "nothing" (without the quotes) is a valid
          possibility. The random choice is done for each individual occurence
          of the letter. You can also give possibilities a "weight," which
          affects their chance of being picked. The default weight is 10. You
          can abbreviate "weight:30" by "w:30". The chance to pick a
          possibility is
          [possibility's weight: / sum of all weight:s in that array position]

          For example, the following line makes letter 'd' into a bread ration
          with 50% chance, or apple or orange with 25% chance each:

            ITEM: bread ration / w:5 apple / w:5 orange

          Modifiers:
          * "q:N" sets the item quantity to N (if N > 0). Does nothing
             if the item is not stackable.
          * "no_uniq" prevents the item from being turned into an artefact.
          * "good_item" makes the builder try to make the item a good one
            (acquirement quality).
          * "acquire" requests the use of the acquirement code itself,
            ensuring that the player gets wearable armour, etc. You can
            also use acquire:<god> to request that the acquired item be
            treated as a god gift. Examples: "acquire any", "acquire armour",
            "acquire:sif_muna book", "acquire:trog weapon".
          * "level:N" sets the object's item level (can't be used with
            "good_item").  If set to -2 then the object's item level will
            be the same as a "*" symbol item (five plus twice the
            vault's level number).
          * "damaged" sets the item plusses to -1..-4.
          * "cursed" gets a curse plus plusses as in "damaged".
          * "any" by itself gives a random choice; you can combine "any" with
            "good_item."
          * "star_item" by itself makes an item equivalent to the "*" glyph.
          * "superb_item" by itself makes an item equivallent to the "|" glyph.
          * "any book", "any misc" etc. gives a random item of that class.
            Valid item class names are: gold, weapon, missile, armour, wand,
            food, scroll, jewelry, potion, book, staff, orb, misc, carrion.
            All of these are usable in map definitions, apart from "orb" and
            "carrion".
          * "race:race_name", where "race_name" is "elven", "dwarven" or
            "orcish"; it can also be "none" or "no_race" to prevent the item
            from being randomly being made racial.  Has no effect if the item
            can't take that kind of racial setting.
            NOTE: Can result in a non-racial item if used with "any" and the
            chosen item isn't compatible with the desired race.
          * "ego:ego_name", where "ego_name" is something like  "running" or
            "fire_resistance", and so on; "none" can be used to prevent the
            item from getting an ego.  The item must be fully specified, so
            trying "any weapon ego:vorpal" or "any armour ego:positive_energy"
            will result in an error.  Trying to give an ego to something which
            can't accept an ego will also result in an error.
          * "unrand:item_name" will make a given unrandom by a given name,
            like "long sword unrand:singing_sword".  Omit any apostrophes
            in the name (e.g, unrand:vampires_tooth).  If the name has
            something between double quotes then use that string (e.g,
            unrand:bloodbane). If the unique already exists, the base item
            will be given instead.
          * "randart" will force a randart.  Most of the above modifiers
            will be ignored, except for "ego" (for weapons only).

            WARNING: While checks are done to make sure that an armour ego
            isn't given to a weapon, a weapon ego to a missile, and so on, and
            also to make sure that egos are only given to armours, weapons and
            missiles, no other checking is done.  Thus it is possible to create
            a demonic weapon of holy wrath or a helmet of running.

          Limitations: You can't specify specific pluses or number of charges.
          You also can't lay down corpses, skeletons, or chunks.

          Randart spell books
          -------------------

          You can specify random artefact spell books using:

          * "any fixed theme book" will generate a book with a fixed theme
            (set of spell schools).
          * "any fixed level book" will generate a book with a fixed set of
            spells around the same level.

          You can further specify artefact spell books using "randbook" and any
          combination of the following tags:

          * "disc:spell_school", the first spell school that should be included
            in the book. For example, "disc:earth" or "disc:ice".
          * "disc2:spell_school" an optional second spell school that can be
            included in the book. Note: specifying two spell schools doesn't
            mean that they will both definitely be included, just that they
            might be.
          * "numspells:number" a number of spells to include in the book. Will
            not always be followed.
          * "slevels:max_levels" the total, combined level of spells to include
            in the book. "slevels:6" will use three level two spells, two level
            three spells, a level two and a level four spell, and so on.
          * "spell:spell" a spell to include in the book. All of "_" will be
            replaced with " " and will be parsed as such.
          * "owner:name" will be used to generate the title of the book if
            provided. For example, "owner:Roxanne" may create "Roxanne's
            Treatise on Mountains".

          NOTE: You can place multiple items on the same square by using the 
          KITEM directive. See that section for more information.

MONS:     (list of monsters)
          These are used to help place specific monsters at specific places
          in a vault. They create an array with up to 7 positions. What's in
          the first position in the array will be used when the dungeon
          builder sees a "1" in the vault definition, the second for "2,"
          etc. Note that if, for example, you place a 3 on the map, but your
          MONS: line has no third position, the 3 will be filled with
          RANDOM_MONSTER. Also note that for entry vaults (D:1), all monsters
          in sight of the hero are removed. This does not hold for plants.
          You can use weights as for ITEM: lines.

          A hydra can be given a specific number of heads by calling it
          an "n-headed hydra" (with a maximum of 20 heads):
              MONS: four-headed hydra

          A slime creature's size can be set to other than normal using
          the prefixes "large", "very large", "enormous" or "titanic":
              MONS: very large slime creature

          Individual monsters may be prefixed with the "generate_awake"
          (without the quotes). Use this sparingly:
              MONS: generate_awake giant beetle

          Individual monsters may be prefixed with the "patrolling"
          (without the quotes). Use this sparingly:
              MONS: patrolling naga guardian

          Monsters can also be given colours that override their default
          colour. Use this *very* sparingly:
              MONS: col:darkgrey fungus

          The colour "any" can be given, in which case a random colour
          will be chosen when the monster is placed.

          You can override the displayed monster tile using the "tile:"
          specifier as follows:
              MONS: rat tile:mons_giant_bat

          In tiles version, this would create a monster that uses the
          'monst_giant_bat' tile, but is otherwise identical to a rat.
          Obviously, this substition of one monster onto another should
          never be used, but it can be useful for customised vault monsters
          if an alternate tile exists. In ASCII mode, this will do nothing.

      You can set the monster's faction by specifying "att:" one of:
          * att:hostile -- the default
          * att:friendly -- tame, will follow you
          * att:neutral -- hostile to both you and att:hostile monsters
          * att:good_neutral -- hostile to att:hostile
          * att:fellow_slime -- tame, won't follow you

          Note that 8, 9, 0 also place monsters (see the table).

          If you want to place a random monster suitable for the level
          the map is generated on, you can use
              MONS: random

          If you want to place a random monster suitable for some other
          place, you can use a place: tag in the monster spec:
              MONS: place:Abyss
          or
              MONS: place:Slime:6

          Using place: with MONS implies that you want a random monster.
          You can also request zombies from random monsters suitable
          for some other depth as:
              MONS: place:Elf:7 zombie
          or
              MONS: place:Zot:5 simulacrum
          or
              MONS: place:Vault:8 spectre

          The available modifiers are "zombie", "skeleton",
          "simulacrum" and "spectre".

          If a monster is a member of a band, you can request that it
          be eligible for band members by adding the keyword "band" to
          the name. For instance:
              MONS: orc warlord band

          Specifying "band" doesn't force bands to be placed - it
          requests that the game use the normal chances of creating a
          band. If you use "band", leave some empty space around the
          monster for its band members to be placed.

          A monster can be given specific items by following the monster
          name with a semi-colon and then with an item list as described
          in ITEM:, but with slashes replaced with pipes and commas replaced
          with periods.  For example:
              MONS: orc ; katana | quick blade . chain mail | scale mail

          will generate an orc wielding either a katana or a quick blade
          and wearing either a chain mail or a scale mail.  Randarts are
          never generated, and ego items are only generated if the ego
          is explicitly stated.  Note that any items that the monster was
          originally generated with will be removed and destroyed.  This
          can be used to force a monster to have no items whatsoever:
              MONS: orc; nothing

          Items given to an orc or an elf will be made orcish or elven
          unless the item's race type is explicitly set otherwise.

          Limitations: If an item in the item list has alternatives,
          there's no way to force all monsters dervied from that monster
          spec to choose the same alternative.  If a monster is given
          a random launcher, there is no way to force the ammo type to
          match the launcher type.

          Overriding Monster Names:
          -------------------------

          Individual monsters can be given names as follows:
              MONS: kobold name:Durwent

          This will cause the monster to appear as "Durwent the kobold".
          Spaces can be placed in the name by substituting them with the _
          symbol. It is worth noting that "the <race>" will be appended
          to all names, which should be considered when coming up with them.

          The name tag is also useable in KMONS. It should be used carefully
          to avoid having multiple monsters named the same (ie, as above,
          and then using the glyph '1' multiple times will result in multiple
          "Durwent the Kobold"s).

          There are three different modifiers that by used on a name:
          name_adjective, name_suffix and name_replace.  name_adjective
          makes the name act as an adjective.  For example:
              MONS: kobold name:ugly name_adjective

          Will cause "An ugly kobold", "The ugly kobold hits you",
          and so on.

          name_suffix does the same, but after the monster's base name:
              MONS: kobold name:wearing_mittens name_suffix

          Will give "A kobold wearing mittens", "The kobold wearing
          mittens hits you", and so on.

          name_replace causes the base name to be replaced by given
          name, as if the monster was a unique:
              MONS: kobold name:Durwent name_replace

          Will result in "Durwent" rather than "Durwent the Kobold".

          In combination with name_replace, there are two further tags that
          can be used when renaming monsters, but not giving them an actual
          "name": name_descriptor, and name_definite.

          For example:
              MONS: kobold name:goblin name_replace

          Will result in "goblin hits you". However, adding name_descriptor
          from the above flags will result in "The goblin hits you" and in the
          description of the monster, "A goblin".
              MONS: kobold name:goblin name_replace name_descriptor

          The name_definite flag ensures that it is never referred to as "a" or
          "an", but that the definite object is always used. Therefore, you will
          see "The goblin hits you", as per above, but also "The goblin" in its
          description. Setting name_definite will automatically set the flag
          name_descriptor, therefore meaning that:
              MONS: kobold name:goblin name_replace name_definite

          Is exactly the same as:
              MONS: kobold name:goblin name_replace name_descriptor name_definite

          This allows for shorter definitions. For instances where space in
          definitions is limited, you can use abbreviated forms of these tags:

              name_suffix     -> n_suf
              name_adjective  -> n_adj
              name_replace    -> n_rpl
              name_descriptor -> n_des
              name_definite   -> n_the

          Monster names should be used very sparingly.

          Overriding Monster Stats:
          -------------------------

          Further monster customisation can be made by using "hd" and "hp".
          These two tags allow you to completely overwrite the original hit dice
          and hit points of a monster:
              MONS: kobold hd:20

          Creates a kobold with a hit dice of 20. As its hp is randomised, based
          on its hit dice, this will also be re-rolled. Monsters with a specific
          hit point value will not have this value change.

          You can also have a specific value for hit points:
              MONS: kobold hp:20

          Creates a kobold with 20 hit points. This is also useful for monsters
          (such as statues) which come with non-randomised HP values.

          Monsters can be marked as summoned by using "dur" and "sum" tags. The
          "dur" tag accepts an integer between 1 and 6 inclusive. The "sum" tag
          accepts the name of a spell (parsed as per the spells tag, described
          below) or any of "clone" (Rakshasa), "animate" (from animate dead),
          "chaos" (made from pure chaos), "miscast" (summoned from by spell
          miscast effect), "zot" (summoned by a Zot trap), "wrath" (summoned by
          a god in an act of retribution), "aid" (summoned by a god in order to
          give aid).

          Of the spells, "shadow_creatures" has the most significant effect, in
          that monsters will dissipate into the shadows rather than disappear in
          a puff of smoke. Using non-summoning spells will also have no effect.

          Tagging a monster with "seen" will override the system and force that
          player to be marked as already viewed; this means that it won't
          generate messages such as "XYZ comes into view".

          Overriding Monster Spells:
          --------------------------
          Monster spell sets can be overridden with a spells: tag,
          used as follows:

              MONS: goblin spells:throw_flame
              MONS: ancient lich spells:symbol_of_torment;ice_storm;ice_storm

          (a list of spell names, spaces replaced with underscores,
          and names separated by ';' with no spaces around the ';' or
          after the spell: prefix)

          Monster spells currently use a limited spell-slot system,
          with these slots:
              1. Bolt spell
              2. Enchantment
              3. Self-enchantment
              4. Misc(1)
              5. Misc(2)
              6. Emergency/escape

          These slots are not hard and fast rules, but it is sometimes
          useful to drop a spell in a specific slot, for instance the
          emergency/escape slot:
              MONS: hobgoblin spells:.;.;.;.;.;teleport_self

          Spell names must exactly match the names in spl-data.h, with
          spaces replaced by underscores. You may use "." or an empty
          string to specify that a slot should be left empty. You can
          force a spell-less monster with:
              MONS: orc wizard spells:.
          (although why you'd want to do this is open to question.)

          If you define spells for a monster that cannot cast spells
          normally, you may want to mark the monster as a real
          spellcaster with 'actual_spells':
              MONS: goblin spells:throw_flame actual_spells

          Or as a priestly (divine) caster with 'priest_spells':
              MONS: goblin spells:smiting priest_spells

          Real spellcasters and priests can be silenced and will
          trigger appropriate conducts (Trog will appreciate killing
          spellcasters, Beogh will appreciate killing priests). If you
          define spells without specifying 'actual_spells' or
          'priest_spells', and the monster cannot cast spells
          normally, the spells will be treated as innate abilities, so
          the monster can use these spells even when silenced.
          Treating spells as innate abilities may produce odd casting
          message (such as: "the rat throws fire at you"). If you find
          the messages you get unsatisfactory, add suitable entries to
          source/dat/database/monspell.txt.


COLOUR:   . = green / blue:5 / red / none
          COLOUR: allows you to attach explicit colours to any feature.
          Explicit colours will override the default colour for that
          feature. The example shown above colours all . (floor) in the
          map green, blue, red, or unchanged (use the default colour).

          You can use : to specify that all glyphs get the same colour:
          COLOUR: x : red / blue
          will colour all rock walls in the map red, or all rock
          walls blue.

          COLOUR: should be used very sparingly, and only for features
          where it won't cause confusion (i.e.: never re-colour features
          like lava or traps unless you really know what you do!)

          If you apply COLOUR to a glyph and then apply a SUBST,
          the COLOUR will transfer to the resulting transformed glyph.

          There are two types of colour available: base and "elemental".
          Available base colours are as follows: blue, green, cyan, 
          red, magenta, brown, lightgrey, darkgrey, lightblue, lightgreen, 
          lightcyan, lightred, lightmagenta, yellow and white. 

          Elemental colours are: fire, ice, earth, electricity, air, poison,
          water, magic, mutagenic, warp, enchant, heal, holy, dark, death,
          necro, unholy, vehumet, beogh, crystal, blood, smoke, slime, jewel,
          elven, dwarven, orcish, gila, mist, shimmer_blue, decay, silver,
          gold, iron, bone, random. See view.h for comments on each.

          Even more so than base colours, elemental colours should be used
          very, very, very sparingly.

FTILE:    . = floor_grass:20 / floor_dirt / none
          Similar to COLOUR, FTILE allows you to attach explicit floor
          tiles to any glyph.  In non-tiles builds, this does nothing.
          If the tile specified has variations, those will be used
          automatically.  Only tiles from the dungeon image can be used.

          This will not (necessarily) replace the feature tile itself,
          only the floor.  If you set the FTILE on a fountain glyph,
          then the fountain will still appear normally, but the floor
          underneath it will be the tile that was specified.

          If a feature that normally covers the floor (e.g. rock walls) is
          destroyed, this floor tile will be used in place of the normal
          floor. Thus, it can be useful even for non-floor features.

          Like COLOUR, this should be used sparingly.

RTILE:    x = wall_hive:15 / wall_lair / none
          Identical to FTILE, but for rock walls.  Not useful for anything
          but the rock wall feature.

TILE:     x = wall_flesh
          Identical to FTILE and RTILE in syntax, but closer to COLOUR in
          functionality. Instead of replacing the floor or relevant rock tiles,
          this can be used to replace the tile used for any specific feature.

          This can be used in combination with FTILE and RTILE to change the
          appearance of features. It can only be used with previously specified
          tiles, however.

          Like COLOUR and FTILE, this should be used sparingly and to good
          effect.

SHUFFLE:  def, 12/3?
          This allows you to randomly permute glyphs on the map. There are
          two ways:

          SHUFFLE: 123w     (i.e. list of glyphs, NOT slash-separated)
          could, for example, swap all occurences of "1" with "2", as well as
          swapping all "3" with "w" (or any other of the 24 possibilities).

          SHUFFLE: 12/3w    (i.e. list of slash-separated blocks of same size)
          will either do nothing or swap all "1" with "3" and then also swap
          "2" with "w" everywhere.

          Several SHUFFLE: lines can be used, and mixed with SUBST:, and the
          shuffles and substitutions will be applied in order. You can also
          put multiple SHUFFLEs on one line, comma-separated. Shuffles cannot
          use , or /. All spaces are stripped before shuffling.

SUBST:    ?=xc, !:bv, 1=2 1:100
          The SUBST: directive allows you to specify a placeholder symbol
          that is replaced with a random glyph from a set. For instance:

          SUBST: ? = TUV
          replaces occurrences of ? with one of TUV. Since whitespaces are
          irrelevant, this is the same as
          SUBST: ? = T U V

          SUBST: ? = T:20 U V
          makes T twice as likely to be used as U or V (the default weight
          is 10). Note that there has to be at least one space before and
          after T:20 and that whitespace in T:20 is not permitted.

          SUBST: ? : TUV
          replaces occurrences of ? with one of TUV, and guarantees that all
          occurrences of ? will get the same replacement symbol.

          The placeholder and replacement symbols can be any non-space,
          printable character, including : and =, apart from commas. For
          example, the following is valid:
          SUBST: = = +=:123def"

          SUBST: lines can safely replace symbols with themselves, as in:
          SUBST: w = wW

          Multiple SUBST: lines can be used, and mixed with SHUFFLE:, and
          will be applied in order. Multiple substitutions can be performed
          on one line, using commas.

NSUBST:   ? = 3:w / *:l

          NSUBST is similar to SUBST, replacing placeholders with
          replacement values. Unlike SUBST, however, it allows you to
          replace different instances of the same placeholder with
          completely different substitutions. For instance:

          ? = 3:w / *:l

          replaces three occurrences (randomly selected) of ? with w
          and all others with l.

          You can use complex SUBST specifications:

          ? = 3= w .:15 A / *: =+CF

          This is equivalent to SUBST: ? = w .:15 A for three ? and
          SUBST: ? : =+CF for all the others.

          You can use any number of NSUBST specifiers:

          ? = wW / l / A / 1234

          Each specifier is preceded by the number of symbols to apply
          it to, followed by : or = (: to use one substitution for all
          occurrences, = to randomly pick for each occurrence). If you
          omit the initial N: or N=, then 1= is assumed, except for the
          last spec where *= is assumed.

KFEAT:    G = C / needle trap / antique armour shop / altar_zin
          The KFEAT: directive allows you to specify a placeholder symbol
          that is replaced with another symbol, named feature, trap, or
          shop. For example, the line above will replace occurrences of G
          with C (random altar), a needle trap, an antique armour shop, or
          an altar of Zin. Different instances of G may receive different
          replacements. To force a single replacement for all G,  use:

          KFEAT: G : C / needle trap / antique armour shop

          You'll notice that 'G' is the symbol of a granite statue. Kxxx
          directives allow you to assign arbitrary definitions to any symbol.

          KFEAT features are specified as a feature name (see section I
          for a full list of feature names). As another example, you can
          place a portal to the Abyss as:

          KFEAT: A = enter_abyss

          If you want no feature as an option in a KFEAT line, use '.' or
          'floor'. If you do not want to specify the type of shop, use
          'any shop' or 'random shop'.

          If you want a trap to start out known to the player, add "known"
          to the trap name:

          KFEAT: A = known needle trap

          The placeholder used by KFEAT can be shared by KITEM and KMONS;
          see below. If the placeholder is shared, all defined Kxxxx
          operations for the placeholder are performed. Also, all Kxxx
          lines accept weights as for MONS or ITEM.

KMONS:    ? = orc priest / w:3 deep elf priest

          KMONS: allows you to specify a placeholder symbol that indicates
          the position of a monster (or monsters).
          Using KMONS: allows you to exceed the 7 slot limit for monsters.
          It is also useful if you want to place a monster on a non-floor
          square (used in association with a KFEAT:). For example,
            KFEAT: Z = W
            KMONS: Z = rat
          places a rat on a shallow water square for all occurrences of Z.

          KMONS: also allows you to specify alternative monsters if the
          primary monster you want to place is unavailable (because it
          is a unique that was already generated). For instance, if you want
          to generate one of Terence, Michael or Erica or a generic human
          (whoever is available, in that order, you can use):
            KMONS: n = Terence, Michael, Erica, human
          Or if you want to pick randomly:
            KMONS: n = Terence / Michael / Erica, human

KMASK:    Z = no_monster_gen

          KMASK allows you set or unset various masks for particular
          symbols, rather than for the entire vault like if you did it
          with TAGS. Valid masks are

          * "no_item_gen":   Prevents random item on that symbol. Items
             explicitly placed on that symbol aren't affected.
          * "no_monster_gen": Prevents random monster generation on that
             symbol. MUST-HAVE for those with water/lava symbols in
             entry vaults.
          * "no_pool_fixup": prevents a water square next to land from being
             randomly converted from deep water (the default) to shallow.
          * "no_secret_doors": prevents a door from randomly being turned
             into a secret door.

          For example

            KMASK: W = no_monster_gen

          will prevent monsters from randomly being generated on shallow water
          squares.  Note that if shuffling and substitutions cause W to end up
          as water 10% of the time and floor 90% of the time, then those floor
          squares will still have no_monster_gen set, but that's still a higher
          degree of control than you get with TAGS.

          If TAGS has been used to set a mask for the entire vault, you can use
          KMASK to remove that mask from particular symbols.  For instance:

            TAGS:  no_monster_gen
            KMASK: W = !no_monster_gen

          would make it so that monsters are only randomly generated on shallow
          water squares.

KPROP:    x = bloody
          KPROP: allows you to assign a specific property to a feature. Like
          KFEAT: and KMONS:, it can be combined with these for the same place-
          holder.

          Available properties are:

          * "bloody": Causes features to appear as though splattered with
             blood. This should be used very, very sparingly!   
          * "no_cloud_gen": Prevents clouds from being generated over this
             feature (usually lava).  Does not stop fog generators or clouds
             entering from nearby squares.
          * "no_rtele_into": Prevents random teleport from chosing to use this
             square. Should be used sparingly.
          * "no_ctele_into": Prevents controlled teleportation into this square.
             Will instead generate the message "A strong magical force throws
             you back!". Should be used sparingly.
          * "no_tele_into": Combines the above no_rtele_into and no_ctele_into
             in one flag, and disallows both random and controlled teleports.

KITEM:    ? = potion of healing / potion of restore abilities
          KITEM: places the specified item at all occurrences of the
          placeholder. It can be combined with KFEAT: and KMONS: lines for
          the same placeholder.

          You can use "gold" or "$" to place gold:
            KITEM: ? = nothing / gold
            KITEM: ? = nothing / $

          You can use q: to specify quantities:
            KITEM: ? = q:100 gold

          KITEM: allows you to place multiple items on the same square:
            KITEM: ? = bread ration, potion of water, potion of porridge

MARKER:   A = feat:<feature_name> or lua:<marker_expr>

          A marker ties a square on the map to a game-trigger of some sort
          (which depends on the marker and what feature it is on).

          The portals to the Hells in the Vestibule of Hell are each annotated
          with feature markers like this:

          MARKER: D=feat:enter_dis, G=feat:enter_gehenna

          When the horn is sounded, the stone arch at D becomes the portal to
          Dis, the arch at G becomes the portal to Gehenna.  This behaviour
          applies only to the Vestibule of Hell.

          Lua markers are used for more complex triggers, such as for bazaar
          and labyrinth gates, rune pickup triggers for the branches of Hell,
          fog generators, etc.

          Here's a Lua marker that creates a cloud generator (for a
          full explanation of the various parameters, read the header
          of dat/clua/lm_fog.lua):

          MARKER:  A = lua:fog_machine { \
                       pow_max = 15, delay_min = 100, delay_max = 150, \
                       size = 1, size_buildup_amnt = 29, \
                       size_buildup_time = 1000 }

          Feature names used in markers must be names matching the names in
          the source code.  There's a full list of feature names in section I
          (Feature names) at the end of this document.

          An important note about markers is that they are also considered map
          transforms along with SUBST, NSUBST and SHUFFLE.  You usually want
          to place a MARKER line after all SUBST, NSUBST and SHUFFLE lines so
          that the final position of the marker key is used.  For instance, if
          you want to attach a marker to the rune in a map which randomises
          the position of the rune, this is a mistake:

          MARKER: O = lua:<expr>
          SHUFFLE: Oa/|c

          because the marker will be placed at O (the rune), then O may be
          shuffled to a different position. The correct order in this case is:

          SHUFFLE: Oa/|c
          MARKER: O = lua:<expr>

SUBVAULT: X : some_vault_tag / some_other_vault_tag:20

          Pick a vault that matches the tag and replace matching glyphs in
          the current map with the cells from that vault.

          Multiple glyphs can be specified on the left hand side and
          weighted sets of tags can be used on the right hand side.

          The use of an equal sign to pick a different subvault per-glyph,
          e.g. "X = some_vault_tag" is not supported at this time.  Use
          a ':' instead to fix the choice of vault tag among all glyphs.

          When a subvault is applied, the first step is finding the smallest
          bounding box around the glyphs.  For example, in the following vault
          definition, the smallest bounding box around the X glyph is a 4x3
          rectangle:

              ......
              ..XXX.
              ..XXX.
              .XXX..
              ......

          After the bounding box is calculated, a valid subvault that matches
          the given tags and is no larger than the bounding box will be found.
          If no subvault can be found, the vault will throw an error.  If a
          subvault is found that is smaller than the provided bounding box,
          then it will be randomly placed and possibly rotated within the
          bounding box.

          There is not much optimization to best fit a subvault into the
          glyphs provided by the parent vault.  So, take some care when using
          non-rectangular subvaults.  The only special case is if you provide
          a subvault that is the exact same shape as what the parent vault
          requests.

          Everything from the subvault cell (feature, items, monsters,
          properties, markers) overwrite the glyph in the parent map.
          Once replaced, this cell is immutable and cannot be changed
          with something like SUBST, MARKER, or KFEAT.

          Additional glyphs that are not replaced by the subvault will be left
          untouched so that the parent vault can replace them with whatever
          feature it desires.  These untouched glyphs can occur either because
          the subvault was smaller than the bounding box or because the
          subvault left the glyph blank (' ').  Because of this, a SUBVAULT
          command should usually be followed by a SUBST command to clean up
          these remaining glyphs.

          Subvaults are allowed to include subvaults themselves, recursively.
          However, there is no checking for infinite loops or cycles of
          subvaults, so use this feature with some care.

          During map verification, the SUBVAULT command does not do anything.
          Therefore, the compilation step for Lua vaults will not catch errors
          where no maps exist for a given tag or where all maps that do exist
          are too big to fit into the provided space in the parent map.  (The
          reasoning for not verifying the subvault command is so that you can
          specify maps by tag that may be defined later in the file or even in
          another file that hasn't been loaded yet.) So, test your subvaults!

          As the size of the subvault may vary depending on the parent vault,
          there are some helpful Lua functions (in the dgn library) that can
          be used to get more information about what the parent vault is
          requesting.  Here's a quick reference:

          is_subvault()

              This function returns true if the current map is being used as a
              subvault and false if the current map is a normal vault.

          local width, height = subvault_size()

              This function returns the width and height of the subvault.
              If not a subvault, it returns 0.

          iter.subvault_iterator(_G)

              Can be used to iterate through all the 0-indexed coordinates
              in the subvault that will get copied back to the parent vault.
              It will return no points if this is not a subvault.

          default_subvault_glyphs()

              This is a convenience function that replaces the current
              subvault map with one that is the exact size of the bounding
              box.  For any valid square that the parent map will replace with
              the subvault, it will place a '.' in the map.  For any invalid
              square that will not be replaced by the subvault, it will place
              a ' ' in the map.  If not a subvault, it does nothing.

              The advantage of this is that a vault author can then use nsubst
              on the '.' feature to ensure that a fixed number of objects will
              be created in the parent vault.

              NOTE: This function will also entirely clear the current map, so
              call it first in the subvault definition.


Handling long lines
-------------------

For most map headers, you can split long lines by ending the line that will be
continued on the next line with \ as:

KMONS: * = orc ; katana | quick blade . chain mail | scale mail / \
           goblin ; dagger

If you're using continuation lines for comma-separated lists of monsters or
items, split your line after the comma, not before.  For example:

Wrong:
        ITEM: potion of healing \
              , potion of speed
Right:
        ITEM: potion of healing, \
              potion of speed

But in general, it is preferable to use multiple ITEM or MONS lines if you're
splitting comma-separated values:

Preferred:
        ITEM: potion of healing
        ITEM: potion of speed

Spaces before the \ of the continued line are significant, leading spaces of
the next (continuing) line are not. In other words, given:

ITEM: potion of\
      healing

Crawl will see "potion ofhealing", not "potion of healing".

Assigning multiple glyphs at once
---------------------------------

Declarations that modify glyphs allow multiple glyphs to be assigned
simultaneously as a convenience.  For example, the following declaration will
assign floor_orc as the tile to be used for all up stair cases and floor:

    FTILE: .[{( = floor_orc

This case is identical to the longer syntax:

    FTILE: . = floor_orc
    FTILE: [ = floor_orc
    FTILE: { = floor_orc
    FTILE: ( = floor_orc

Using : instead of = while assigning glyphs will assign the same value to all
glyphs.  In the following example, the glyphs A, B, and C will either all
contain gold or all contain nothing:

    KITEM: ABC : gold / nothing

Note: The number of items assigned in an NSUBST expression applies to the
entire group of glyphs being assigned.  For example:

    # Among all A, B, and C glyphs, make one a floor and the rest walls.
    NSUBST: ABC = 1:. / *:x

    # Make one A glyph floor, one B glyph floor, and one C glyph floor.
    # Make the rest of the A, B, and C glyphs walls.
    NSUBST: A = 1:. / *:x
    NSUBST: B = 1:. / *:x
    NSUBST: C = 1:. / *:x