herpmino Level 1 of the Dungeon (4, -6, D:1) a +0 dagger (8, -9, D:1) 25 stones (10, 29, D:1) a +0 helmet (12, -2, D:1) a +0 short sword 4 stones (13, 1, D:1) a +0 dagger (26, 5, D:1) a +0 short sword (31, 16, D:1) 14 stones (38, 11, D:1) a +0 short sword (48, 6, D:1) a +0 club (unseen) (50, 4, D:1) a +0 club Level 2 of the Dungeon (0, 0, D:2) a +0 spear (4, 4, D:2) a +0 scale mail (12, 10, D:2) 17 sling bullets (22, 16, D:2) a +0 club (58, 7, D:2) a +0 leather armour (60, 15, D:2) a +0 helmet Level 3 of the Dungeon (0, 0, D:3) 20 poisoned needles (6, 1, D:3) a +0 helmet (10, 7, D:3) a stone (10, 31, D:3) a +0 hunting sling 29 stones a +0 dagger a +0 robe a +0 flail (11, 23, D:3) 17 stones (12, 24, D:3) a +1 leather armour of cold resistance (13, 26, D:3) a cursed -3 dagger (13, 28, D:3) a stone (14, 14, D:3) a +0 hunting sling (15, 18, D:3) 20 stones (15, 20, D:3) a +0 dagger a +0 spear (33, -4, D:3) an uncursed staff of wizardry (39, -6, D:3) a +0 club (46, 3, D:3) a +0 club a +0 dagger (47, 4, D:3) 10 bolts (50, 1, D:3) a +2 dagger of venom a +0 ring mail a +0 whip (50, 17, D:3) 28 sling bullets (50, 21, D:3) a +0 dagger (56, 25, D:3) a +0 club (57, -9, D:3) a +0 dagger a +0 robe a +0 club (57, 10, D:3) 5 tomahawks (63, -6, D:3) a +1 dagger of venom Level 4 of the Dungeon (0, 0, D:4) 21 stones (15, -1, D:4) 25 arrows (22, 3, D:4) 16 stones (34, 17, D:4) a +0 robe (44, -27, D:4) a +0 dagger Level 5 of the Dungeon (0, 0, D:5) a +0 club (2, -48, D:5) a +0 dagger a +0 robe (3, -49, D:5) a +0 dagger a +0 robe (11, 0, D:5) 21 stones (16, -15, D:5) a +0 club (16, -13, D:5) a +0 falchion a +0 scale mail (17, -13, D:5) a +0 hand axe a +0 leather armour (25, -35, D:5) a +0 giant spiked club (28, -23, D:5) a +0 ring mail (34, -20, D:5) 23 stones (37, -12, D:5) a +0 chain mail Level 6 of the Dungeon (0, 0, D:6) a +0 hand axe Level 7 of the Dungeon (3, 2, D:7) a +0 flail a +0 whip a +0 club a +0 spear a cursed -2 ring mail a +0 shortbow 26 arrows (10, 3, D:7) a +0 robe (17, 11, D:7) a +0 ring mail (22, 11, D:7) a +0 long sword a +0 plate armour (22, 12, D:7) a +0 short sword (unseen) (30, -22, D:7) 16 sling bullets (32, -17, D:7) a +0 hand axe a +0 mace a cursed +0 leather armour Level 8 of the Dungeon (5, -7, D:8) a +0 dagger a +0 robe (6, -7, D:8) a +0 dagger a +0 robe a +0 scimitar a +0 chain mail (7, -3, D:8) a +0 dagger a +0 ring mail a +0 trident a +0 leather armour a +0 dagger a +0 robe (9, 6, D:8) 24 sling bullets (11, 9, D:8) 14 stones (12, -6, D:8) 18 bolts (12, 23, D:8) a +0 ring mail (still there?) a +0 robe (still there?) (13, 25, D:8) a +0 giant spiked club (18, 1, D:8) 24 stones (27, 31, D:8) a +0 scimitar (29, -9, D:8) a +0 war axe (29, -5, D:8) 19 bolts (34, -17, D:8) 10 arrows (36, -8, D:8) a +0 trident (37, -9, D:8) a +1 hand axe of electrocution (38, -2, D:8) a +0 dagger (47, -18, D:8) a +0 robe (47, 4, D:8) 16 stones (47, 10, D:8) a +0 flail (47, 11, D:8) a +0 dagger a +0 robe (47, 21, D:8) a +0 war axe a +0 hand axe a +0 leather armour a +0 mace 4 tomahawks (50, 11, D:8) a +0 falchion a +0 hand axe a +0 leather armour (58, 19, D:8) a +0 dagger a +0 leather armour Level 9 of the Dungeon [Shop] Curu Loude's Distillery a potion of curing (42 gold) a potion of haste (140 gold) (0, 0, D:9) a +0 quarterstaff (3, -14, D:9) 18 stones (7, 14, D:9) a +0 giant club (12, -18, D:9) a +0 dagger a +0 robe (12, 14, D:9) a +0 trident (47, 16, D:9) 22 stones (47, 17, D:9) a crystal ball of energy (47, 18, D:9) 3 fruits (48, 15, D:9) a box of beasts (48, 19, D:9) a +1 demon whip of electrocution (49, 15, D:9) a +0 morningstar (unseen) (49, 19, D:9) a manual of Spellcasting (50, 15, D:9) the +2 short sword of Fedhas's Condemnation {elec, Str+2} Occasionally, upon striking a foe, it will discharge some electrical energy and cause terrible harm. It affects your strength (+2). (50, 19, D:9) a wand of enslavement (15/24) (51, 10, D:9) 13 gold pieces (51, 16, D:9) a wand of polymorph (10/24) (51, 17, D:9) a +0 shortbow of freezing (51, 18, D:9) 12 stones Level 10 of the Dungeon (0, 0, D:10) a +0 leather armour (1, 3, D:10) the +10 rapier "Newt's Doom" {flame, *Drain +Inv rPois MR+} It has been specially enchanted to burn those struck by it, causing extra injury to most foes and up to half again as much damage against particularly susceptible opponents. It protects you from poison. It affects your resistance to hostile enchantments. It lets you turn invisible. It causes draining when unequipped. (20, 7, D:10) a +0 whip (21, 4, D:10) a +0 halberd (21, 5, D:10) a +2 whip of flaming (unseen) (21, 6, D:10) a +0 flail (21, 7, D:10) a +0 spear (28, -1, D:10) a +0 flail of holy wrath (unseen) (29, 5, D:10) a +0 giant club a +0 giant club (30, 1, D:10) a +0 club a +0 flail 2 tomahawks (31, -1, D:10) a +0 dire flail a +0 giant club (31, 1, D:10) a +0 leather armour a +0 whip of freezing (31, 5, D:10) a +0 leather armour a +0 club (32, -16, D:10) a +0 robe (32, -2, D:10) a tomahawk (32, -1, D:10) a +0 leather armour (unseen) (39, -25, D:10) a +0 leather armour (unseen) (39, -24, D:10) 18 arrows a +0 shortbow (46, 2, D:10) a +0 hand axe a +0 chain mail (47, -1, D:10) a +0 whip a +0 ring mail (47, 0, D:10) 2 tomahawks of returning a +0 mace (47, 1, D:10) a +0 club (48, -3, D:10) a +0 club (still there?) a +0 mace (still there?) (48, -2, D:10) a +0 whip a +0 falchion a +0 short sword of freezing a +0 dagger a cursed -2 robe (49, -4, D:10) a +0 dagger (unseen) (49, -3, D:10) a +0 dagger a +0 whip a +0 mace a cursed +0 leather armour a +0 dagger a +0 robe (50, 0, D:10) a +0 trident (unseen) (52, -2, D:10) a +0 chain mail (57, -1, D:10) 15 stones (59, 4, D:10) a +0 short sword Level 11 of the Dungeon (0, 0, D:11) a +0 scimitar (13, -3, D:11) a +0 great sword (15, -7, D:11) 24 arrows (20, 4, D:11) 2 fruits (20, 26, D:11) a +0 leather armour (30, 17, D:11) 22 arrows (31, 26, D:11) a +0 dagger (31, 38, D:11) a +0 flail a +0 spear a +0 war axe a +0 battleaxe a cursed -1 chain mail (33, 15, D:11) 15 sling bullets (39, 24, D:11) a +0 leather armour (unseen) (40, 23, D:11) a +0 quarterstaff (unseen) (40, 24, D:11) a +0 war axe (still there?) a +0 flail (still there?) (40, 25, D:11) a +0 robe (unseen) (41, -7, D:11) a +0 cloak (41, 23, D:11) a +0 war axe (41, 24, D:11) 3 large rocks (41, 29, D:11) a +0 robe (44, 23, D:11) a scroll of identify (45, 17, D:11) a +0 spear (unseen) (53, -5, D:11) a +2 dagger of draining a +0 robe Level 12 of the Dungeon (1, -2, D:12) a +0 scale mail (unseen) (8, -7, D:12) a poisoned needle (9, 4, D:12) a +0 halberd (14, -7, D:12) a poisoned needle a curare-tipped needle (15, -7, D:12) a +0 club a +0 short sword 2 poisoned needles a +0 short sword a +4 blowgun (16, -8, D:12) 6 poisoned needles a +0 blowgun a +0 club (16, -7, D:12) a curare-tipped needle a +3 dagger a +4 blowgun (18, -9, D:12) a poisoned needle (21, -7, D:12) a curare-tipped needle (24, 12, D:12) a curare-tipped needle (26, 14, D:12) a curare-tipped needle (36, 4, D:12) a +0 blowgun a +1 dagger of draining 6 curare-tipped needles (40, 0, D:12) a +0 helmet Level 13 of the Dungeon (0, 0, D:13) 17 arrows (7, 20, D:13) a +0 short sword a +0 longbow 16 arrows a +0 leather armour a +0 giant club a +0 giant club (13, 21, D:13) an arrow (17, 20, D:13) a +0 war axe a cursed +0 chain mail (17, 24, D:13) an arrow (19, 8, D:13) a +0 club a +2 robe a +0 giant club (25, 2, D:13) a +0 halberd (25, 3, D:13) a +0 trident (34, 13, D:13) a +0 robe a +0 long sword (47, 27, D:13) a +0 shortbow (56, 3, D:13) a +0 flail a +0 battleaxe a +0 halberd a +0 plate armour (57, 3, D:13) a +0 scimitar (58, 3, D:13) a +3 leather armour (unseen) Level 14 of the Dungeon (0, 0, D:14) a +0 whip (3, 11, D:14) 18 sling bullets (4, -15, D:14) a cursed +4 war axe (unseen) (5, -17, D:14) 2 curare-tipped needles (5, -10, D:14) a +0 scale mail (7, -7, D:14) a cursed +0 great sword (unseen) (8, -7, D:14) a +0 dire flail of crushing (unseen) (9, -1, D:14) a +0 scimitar of flaming (10, 2, D:14) a +0 halberd (12, -2, D:14) 24 sling bullets (19, -6, D:14) a cursed -1 dire flail a +0 plate armour (20, -17, D:14) a +0 pair of boots (22, -17, D:14) a cursed -1 giant club (28, 11, D:14) a wand of iceblast (12/15) (29, 10, D:14) a cursed -3 giant club (35, 13, D:14) a +0 great mace a +0 chain mail (38, 10, D:14) a +0 chain mail (40, 10, D:14) a +2 war axe a cursed +0 plate armour a +1 great mace a +0 chain mail (41, -24, D:14) a +1 dagger of venom (41, 18, D:14) a +0 plate armour a +0 great sword (43, -22, D:14) a +0 dagger of electrocution a +0 club a +0 leather armour a +0 dagger 4 tomahawks of returning (44, -23, D:14) a +0 giant club a +0 club a +0 leather armour a +0 flail a cursed +0 leather armour a +0 hand axe (44, -22, D:14) a +0 falchion a +0 giant club a +0 short sword a +0 club a +0 flail a +0 scale mail (45, -22, D:14) a tomahawk of returning (45, -21, D:14) a +0 trident a +0 chain mail (46, -22, D:14) a +2 war axe of chopping a +0 chain mail a +1 trident of holy wrath a +0 plate armour a +0 mace a +0 plate armour a +0 short sword of speed 5 tomahawks a +0 chain mail a +0 halberd a +0 chain mail a +0 war axe a +0 chain mail (46, 20, D:14) a +0 ring mail a +3 battleaxe of freezing (51, 0, D:14) 15 arrows (52, 9, D:14) a cursed ring of loudness Level 15 of the Dungeon (0, 0, D:15) an uncursed ring of fire a +2 ring of protection a +2 plate armour of magic resistance a +1 chain mail of magic resistance a +0 shield an uncursed ring of stealth (1, 0, D:15) a potion of degeneration (7, -5, D:15) a cursed -3 mace (unseen) (7, -4, D:15) a +2 glaive of flaming a +0 chain mail (8, -5, D:15) a +0 trident a +0 robe a scroll of recharging (28, 43, D:15) a +0 dire flail a +0 giant club (29, 43, D:15) a +0 rapier (30, 23, D:15) a +0 short sword (33, 46, D:15) a +0 giant club (34, 46, D:15) a +0 giant club a +0 giant spiked club (36, 10, D:15) a +0 club (unseen) (36, 11, D:15) a +0 dagger a +0 club a cursed -2 morningstar a +0 club a cursed +0 scale mail a +0 hand axe a +0 war axe a +0 leather armour 58 gold pieces (36, 12, D:15) a +1 falchion of freezing (unseen) (36, 45, D:15) a +1 robe of positive energy a +0 whip (36, 48, D:15) a +0 troll leather armour a +0 giant club a +0 great mace of draining (37, 11, D:15) a +0 halberd a +0 plate armour (43, 9, D:15) a +0 dagger a +0 leather armour (43, 30, D:15) a +2 falchion of draining (45, 17, D:15) 15 gold pieces (unseen) (45, 31, D:15) a tomahawk a cursed -2 dagger (45, 33, D:15) 19 arrows (unseen) (46, 33, D:15) 2 arrows (47, 26, D:15) a +0 giant club a +0 dire flail (47, 31, D:15) a +0 chain mail a +0 hand axe (47, 32, D:15) 2 arrows a +0 robe a +1 spear (48, 31, D:15) a +0 robe a +4 mace a +0 shortbow 19 arrows a +0 halberd a +0 robe (48, 32, D:15) 2 arrows (49, 31, D:15) a +0 shortbow a +0 ring mail a +0 shortbow 26 arrows (49, 32, D:15) 44 arrows a +1 robe of cold resistance a cursed -2 shortbow a +0 shortbow a +0 falchion a +0 robe a cursed +0 war axe (50, 33, D:15) 5 arrows (51, 6, D:15) 2 arrows (51, 18, D:15) an arrow (51, 22, D:15) 2 arrows (52, 6, D:15) an arrow (52, 17, D:15) 2 arrows (52, 21, D:15) an arrow (53, 4, D:15) an arrow (53, 6, D:15) an arrow (53, 16, D:15) 4 arrows a +0 ring mail a +0 club (53, 20, D:15) 2 arrows (54, 5, D:15) 2 arrows (54, 6, D:15) 2 arrows (54, 15, D:15) a +0 hand axe a +0 leather armour a +0 shortbow a cursed -1 shortbow 20 arrows (54, 19, D:15) an arrow (55, 2, D:15) an arrow (57, 6, D:15) a +0 whip (unseen) (58, -7, D:15) 18 stones (58, 6, D:15) a +0 giant club (58, 8, D:15) a +0 dagger a +0 robe (58, 9, D:15) a +0 hand axe a +0 plate armour (65, 3, D:15) a +0 giant club a +0 giant spiked club a +0 troll leather armour (65, 4, D:15) a +0 giant club a +0 club a +0 chain mail (68, -2, D:15) a +0 club a +0 chain mail a +0 whip a +0 robe a +0 shortbow the Ecumenical Temple Level 1 of the Orcish Mines (0, 0, Orc:1) a tomahawk (2, 4, Orc:1) a tomahawk (3, 4, Orc:1) a tomahawk (4, 4, Orc:1) a tomahawk a +0 club (4, 5, Orc:1) a +0 club (6, 6, Orc:1) a +0 war axe 4 tomahawks a +0 plate armour (7, 35, Orc:1) a +0 dagger (8, 35, Orc:1) a +1 mace of protection a +0 ring mail a +0 flail a +0 chain mail a +0 dagger of protection a +0 robe (14, 47, Orc:1) a +0 short sword (unseen) (15, 45, Orc:1) a +0 mace a +0 chain mail (15, 47, Orc:1) a +0 hand axe a +1 leather armour of fire resistance a +0 flail of holy wrath a +0 flail a +0 chain mail (16, 45, Orc:1) a +0 dagger a +0 robe a +0 mace a +0 leather armour (16, 46, Orc:1) a +0 giant club (16, 47, Orc:1) a +1 great mace of venom a +0 chain mail (17, 16, Orc:1) a large rock (17, 20, Orc:1) a +0 dagger a +0 robe (19, 30, Orc:1) a +0 short sword a +0 leather armour a +0 dagger a +0 robe (20, 13, Orc:1) a large rock (21, 29, Orc:1) a +0 ring mail (unseen) (22, 29, Orc:1) a +0 dagger (unseen) (22, 30, Orc:1) a +0 dagger (unseen) (23, 10, Orc:1) a large rock (24, 13, Orc:1) a cursed +0 club (unseen) (24, 48, Orc:1) a +3 dagger (unseen) (26, 19, Orc:1) a +1 dagger of speed a +0 robe 69 gold pieces (28, 20, Orc:1) a +0 mace (29, 19, Orc:1) a +0 dagger (unseen) (29, 20, Orc:1) a +0 broad axe a +0 plate armour a +0 short sword (29, 21, Orc:1) a +0 glaive (unseen) Level 2 of the Orcish Mines [Shop] Viteif's Weapon Shoppe a +0 dagger (24 gold) a +0 quarterstaff (48 gold) a +0 spear (36 gold) a +0 blowgun (30 gold) a +0 war axe (42 gold) a +0 hand axe (36 gold) a +0 dagger (24 gold) a +0 flail (42 gold) a +4 blowgun (294 gold) [Shop] Siusch's Weapon Shoppe the +5 mace of Uhill {crush, +Inv MR++ Dex-5 Stlth+} (530 gold) It inflicts extra damage upon your enemies. It affects your dexterity (-5). It affects your resistance to hostile enchantments. It lets you turn invisible. It makes you more stealthy. a +2 rapier of electrocution (264 gold) 14 arrows (33 gold) a +1 hand axe of venom (127 gold) a +0 great sword (78 gold) a +0 quarterstaff (48 gold) the +7 sceptre of Torment (1440 gold) 11 poisoned needles (52 gold) a +4 fustibalus of freezing (588 gold) a +5 battleaxe of freezing (464 gold) [Shop] Peneptapt's Magic Scroll Shoppe 3 scrolls of random uselessness (42 gold) a scroll of amnesia (49 gold) a scroll of teleportation (42 gold) a scroll of amnesia (49 gold) a scroll of teleportation (42 gold) a scroll of remove curse (42 gold) [Shop] Guseg's General Store 23 arrows (69 gold) a +0 ring mail (60 gold) +1 ice dragon scales (1005 gold) a bread ration (75 gold) a fruit (22 gold) 20 stones (30 gold) (0, 0, Orc:2) a +0 flail a +0 mace a +0 ring mail a +0 trident a +0 leather armour (1, -1, Orc:2) a +0 battleaxe a +0 plate armour a +0 war axe a +0 chain mail a +0 battleaxe a +0 chain mail a +0 war axe a +0 chain mail a +0 war axe a +0 plate armour a cursed -1 long sword a +0 chain mail (1, 3, Orc:2) a +0 halberd (unseen) (3, 0, Orc:2) a +0 club (unseen) (3, 1, Orc:2) a +0 dagger (3, 18, Orc:2) a +0 great mace a +0 plate armour a +0 battleaxe a +0 chain mail a +0 mace a +0 chain mail (4, 19, Orc:2) a cursed -1 mace a +0 leather armour a +0 hand axe a +0 club a +0 halberd a +0 plate armour (5, 18, Orc:2) a +0 halberd a +0 chain mail (6, 4, Orc:2) a +0 flail (still there?) a +0 mace (still there?) (6, 5, Orc:2) a +0 falchion (6, 17, Orc:2) a +0 short sword (7, 4, Orc:2) a +0 mace (unseen) (8, 4, Orc:2) a +0 short sword a +0 mace a +0 plate armour (8, 5, Orc:2) a +0 giant club (unseen) (8, 6, Orc:2) a +0 mace (unseen) (9, -1, Orc:2) a +0 club (unseen) (9, 3, Orc:2) a +0 short sword (10, 6, Orc:2) a +0 mace a +0 scale mail (20, 1, Orc:2) a +0 war axe a +0 hand axe a +0 chain mail a +0 trident a +0 plate armour a +2 hand axe of freezing (21, -1, Orc:2) a +0 club (unseen) (21, 0, Orc:2) a +0 hand axe a +0 plate armour a +0 ring mail (21, 1, Orc:2) a +0 short sword a +0 scale mail a +0 mace a +0 mace a +0 leather armour a +0 flail a +0 leather armour (33, 40, Orc:2) a +0 giant club (35, 1, Orc:2) a +0 club (35, 2, Orc:2) a +0 war axe a cursed -2 chain mail (36, 34, Orc:2) a +0 leather armour a +0 dagger (39, 3, Orc:2) a +0 trident a +0 plate armour (40, 1, Orc:2) a +0 short sword a +0 glaive a +0 chain mail (40, 2, Orc:2) a +0 war axe a +0 plate armour a +2 short sword of venom a +0 ring mail (40, 33, Orc:2) a +0 chain mail (unseen) (40, 34, Orc:2) a +0 leather armour a +0 ring mail a +0 dagger a +0 halberd a +0 plate armour (40, 35, Orc:2) a +0 giant club (41, 1, Orc:2) a +0 glaive a +0 chain mail (41, 3, Orc:2) a +0 glaive (unseen) (42, 2, Orc:2) a +0 mace a +0 leather armour (53, 0, Orc:2) a wand of iceblast (0/15) a wand of lightning (0/15) an uncursed ring of poison resistance (53, 1, Orc:2) a scroll of teleportation a potion of haste a scroll of random uselessness a potion of brilliance (54, 0, Orc:2) a scroll of noise (55, 30, Orc:2) a +0 short sword Level 1 of the Elven Halls (0, 0, Elf:1) a +1 battleaxe of venom (2, 4, Elf:1) 26 gold pieces (5, -25, Elf:1) a +0 short sword a +0 chain mail (10, 3, Elf:1) a +0 hunting sling (12, -17, Elf:1) a +2 glaive of distortion (13, -35, Elf:1) a +0 short sword (unseen) (13, -33, Elf:1) a +0 short sword (unseen) (20, -16, Elf:1) a +0 blowgun (21, 6, Elf:1) a scroll of teleportation (27, 0, Elf:1) a +0 short sword an elf corpse (skeletalised by now) (30, 0, Elf:1) a +0 long sword a +0 leather armour an elf corpse (skeletalised by now) (31, -30, Elf:1) a +0 robe (36, -31, Elf:1) a +2 rapier of protection (37, -9, Elf:1) an arrow (41, -14, Elf:1) an arrow (41, -12, Elf:1) an arrow (41, -11, Elf:1) an arrow a +0 short sword (41, -9, Elf:1) an arrow (41, -8, Elf:1) a +0 long sword a +0 leather armour (42, -8, Elf:1) a +0 dagger (43, -18, Elf:1) a +0 shortbow (unseen) (49, -24, Elf:1) an arrow (50, -24, Elf:1) 18 gold pieces (51, -21, Elf:1) an arrow Level 2 of the Elven Halls (0, 0, Elf:2) an arrow (4, -3, Elf:2) 4 arrows (6, -4, Elf:2) an arrow (7, -5, Elf:2) an arrow (10, 4, Elf:2) a +0 rapier a +0 leather armour a +0 long sword a +0 shortbow a +0 chain mail a +2 scimitar of slicing a cursed -1 short sword a +0 shortbow 29 arrows an elf corpse an elf corpse (11, 4, Elf:2) a +0 short sword of freezing a +1 flail of draining (12, 6, Elf:2) a +1 eveningstar of pain (13, 7, Elf:2) a +3 dire flail of draining a +0 scimitar an elf corpse Level 3 of the Elven Halls (0, 0, Elf:3) a +0 rapier a +0 ring mail (1, 1, Elf:3) a +0 short sword of electrocution a +2 ring mail of positive energy a +0 scimitar (2, 0, Elf:3) a +0 long sword a +0 leather armour an elf corpse (2, 1, Elf:3) a +0 rapier a +0 long sword (2, 3, Elf:3) a scroll of blinking a +2 ring of strength (2, 14, Elf:3) a wand of paralysis (14/24) (8, -3, Elf:3) 10 sling bullets (13, 9, Elf:3) 2 potions of mutation