Small trick for defeating Shambler easy, bang a sniper mod on a chaingun/assault rifle and as soon and you pull the lever shoot to your left until win.
EDIT:
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DoomRL (v.0.9.9.3) roguelike post-mortem character dump
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Boris Berko, level 16 Imp Sergeant Major, nuked the Cyberdemon.
on level 26 of the Phobos base.
He survived 265458 turns and scored 207290 points.
He played for 3 hours and 57 seconds.
He didn't like it too rough.
He killed 686 out of 686 hellspawn. (100%)
This ass-kicking marine killed all of them!
He saved himself once.
-- Special levels --------------------------------------------
Levels generated : 10
Levels visited : 10
Levels completed : 10
-- Awards ----------------------------------------------------
Medal of Prejudice
UAC Star (silver cluster)
Gambler's Shield
Aurora Medallion
Explorer Badge
Conqueror Badge
Grim Reaper's Badge
Angelic Badge
Hell Champion Medal
Hell Armorer Badge
Technician Gold Badge
Armorer Silver Badge
Heroic Bronze Badge
Longinus Gold Badge
Arachno Bronze Badge
-- Graveyard -------------------------------------------------
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-- Statistics ------------------------------------------------
Health 57/50 Experience 124890/16
ToHit Ranged +0 ToHit Melee +2 ToDmg Ranged +4 ToDmg Melee +7
-- Traits ----------------------------------------------------
Finesse (Level 3)
Hellrunner (Level 1)
Son of a bitch (Level 4)
Reloader (Level 2)
Brute (Level 1)
Whizkid (Level 2)
Triggerhappy (Level 2)
Ammochain (Level 1)
Fin->Fin->WK->WK->SoB->SoB->TH->TH->Rel->Rel->MAc->SoB->Fin->Bru->HR->SoB->
-- Equipment -------------------------------------------------
[a] [ Armor ] cybernano Cybernetic Armor [11]
[b] [ Weapon ] modified plasma rifle (1d7)x12 [40/40] (F3S1T1)
[c] [ Boots ] gravity plasteel boots [4/4] (100%)
[d] [ Prepared ] high power Railgun (8d11) [20/20]
-- Inventory -------------------------------------------------
[a] modified laser rifle (1d10)x7 [40/40] (F1P3)
[b] nanomachic missile launcher (6d6) [6/6]
[c] nuclear plasma rifle (1d6)x6 [24/24]
[d] nanomachic BFG 9000 (10d8) [169/169]
[e] ripper (12d6)
[f] Longinus Spear (8d8)
[g] power cell (x20)
[h] large med-pack
[i] large med-pack
[j] large med-pack
[k] large med-pack
[l] large med-pack
[m] large med-pack
[n] phase device
[o] envirosuit pack
[p] power mod pack
[q] sniper weapon pack
[r] shockwave pack
-- Kills -----------------------------------------------------
119 former humans
63 former sergeants
24 former captains
84 imps
77 demons
90 lost souls
32 cacodemons
35 barons of hell
1 Cyberdemon
23 hell knights
24 arachnotrons
1 John Carmack
4 former commandos
1 Angel of Death
4 pain elementals
10 arch-viles
6 mancubi
7 revenants
2 bruiser brothers
77 shamblers
1 lava elemental
1 Arena Master
-- History ---------------------------------------------------
He started his journey on the surface of Phobos.
On level 3 he entered Hell's Arena.
He left the Arena as a champion!
On level 5 he stormed the Chained Court.
He defeated the Hell Arena Master!
On level 5 he found the Arena Master's Staff!
On level 9 he witnessed the Wall.
He massacred the evil behind the Wall!
On level 10 he entered Hell's Armory.
On level 10 he assembled a assault rifle!
On level 10 he assembled a grappling boots!
On level 10 he found the Cybernetic Armor!
On level 10 he found the Onyx Armor Pack!
On level 10 he found the Nano Pack!
On level 10 he assembled a cybernano armor!
On level 10 he assembled a focused double shotgun!
On level 10 he assembled a ripper!
On level 10 he assembled a tactical shotgun!
On level 10 he assembled a nanomanufacture ammo!
He destroyed the evil within and reaped the rewards!
On level 12 he assembled a gravity boots!
On level 14 he ventured into the Halls of Carnage.
On level 14 he assembled a nanomanufacture ammo!
On level 15 he encountered the Phobos Hellgate.
On level 16 he invaded the Unholy Cathedral!
On level 16 he found the Longinus Spear!
He then destroyed the Unholy Cathedral!
On level 18 he ventured into the Spider's Lair.
He cleared the Lair, kickin' serious spider ass!
On level 19 he assembled a gravity boots!
On level 19 he entered the Vaults.
On level 19 he found the Railgun!
He cracked the Vaults and cleared them out!
On level 22 he was foolish enough to enter the Mortuary!
On level 22 he assembled a high power weapon!
He managed to clear the Mortuary from evil!
On level 23 he entered the Lava Pits.
He managed to clear the Lava Pits completely!
Then at last he found Phobos Arena!
He nuked level 25!
He defeated the Cyberdemon and found the TRUE EVIL!
He nuked level 26!
Then finally in hell itself, he killed the final EVIL.
-- Messages --------------------------------------------------
Fire -- Choose target...
You see : floor
Are you sure you want activate the thermonuclear bomb? [Y/n] You use a
thermonuclear bomb. Warning! Explosion in 10 seconds! Warning!
Explosion in 9 seconds!
Warning! Explosion in 8 seconds!
Warning! Explosion in 7 seconds!
Warning! Explosion in 6 seconds! You feel vulnerable again.
Warning! Explosion in 5 seconds!
Warning! Explosion in 4 seconds!
Warning! Explosion in 3 seconds!
Warning! Explosion in 2 seconds!
Warning! Explosion in 1 seconds!
You use a lava element. You feel invincible! You hear an explosion! You
feel relatively safe now. Congratulations! You defeated John
Carmack! Press <Enter>...
-- General ---------------------------------------------------
Before him 15 brave souls have ventured into Phobos:
13 of those were killed.
And 1 couldn't handle the stress and committed a stupid suicide.
Some rumours though, say that the Cyberdemon was killed already!
Is he immortal? 1 souls claim to have killed him...
1 killed the bastard and survived.
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