Using 1e Modules for 4e: Quick and Dirty Conversion
by, 08-02-2012 at 04:39 PM (3859 Views)
I was greatly influenced by the 1 page free game Searchers of the Unknown which premise was to create and play characters the same as monster stats for the purpose of playing 1e modules. I was nostalgic in the old days when a monster stat was two or three lines rather than a mountain of information, and in 4e, a table of information that took up space.
Using AD&D stat blocks for 4e monsters
The point of this exercise is to allow a DM to use a 1e module to play a 4e game without having to recreate monsters and other aspects to the 4e mechanic. It is loose and dirty to do this but can be useful for a quick game with a pre-design module. In all, this minimalist approach does under-power the monsters though in alater post I will talk about on the fly powers you can add to creatures.
The mechanics of a 1e dungeon crawl is much different than a 4e dungeon crawl. A single monster would be considered a challenge to many PC's where as in 4e, bands of monsters is the standard. For 1e conversion on monster stats, some of the wacky mechanics of 1e (descending AC, for example) needed to have some interesting conversion to make it work. Naturally, you can replace the monsters with full 4e stats of any reskinned monster but one of the things I am trying to do is Limit the amount of info I need to play a monster.
If you go the minimalist route, you might want to emphasize the role-playing aspect of your game so PC's don't waste their time customizing their PC for combat alone.
Some of this conversion will help if you know some the rules and spell mechanics of 1e in order to get full understanding of the conversion. It will also make the on-the fly powers much easier (next post).
Level= HD rounded up (ex ½ HD is level 1). Level/HD will only effect AC, attack bonus, damage, and skill checks. In Ad&D, some monsters will have a HD 1+1, the additional plus will be used as well in some mechanics.
Speed= MV rate/2 or final speed score with the lowest being 4 and max being 10. Typically, a creature with a high movement is quicker and more agile. In some modules the movement will be listed as or as feet or list the outdoor movement versus the indoor movement (because in 1e you moved your movement in yards outdoors and feet indoors). Divide the final number by 10 if it is in feet and it should give you a range of 3-10 speed. Most monster ranger 4, 5,6,7 & 8 with some slow monsters at 4 and max at 10. I would upgrade their movement to at least 4 and no higher than 10.
Initiative = Speed score +2 or if your in hurry just the speed score. You may also opt just the MV score but you could end up with a creature with a +21 initaive at level 8, which is ridiculous.
Armor Class = Armor class is the biggest problem in 1e to 4e conversion.
In addition, while AD&D uses a max of -10 to AC, Basic and Expert D&D only go to AC 0, which greatly effects the AC of high level monsters.
You have 2 options on the AC: A) Try and use what's written for a conversion or use a scaling system (what I recommend)
Using what is written: A Simple conversion is to subtract the AC from 20 to get the armor class. Armor class in 1e however is mostly based on armor and Dex unless it is a monster. This will leave you with AC's that are pretty low and not scaled. A creature with AC 7 (Leather +Shield or ringmail) would translate in a armor class of 13. Not a very high number to beat with some character builds. Another alternative is to use 22 -monster AC. (ex AC 7 creature would be AC 15 in 4e. AC is used for all defenses). It would be more accurate in numbers but takes more math than a simple 20-AC.
Scaling: The more effective model is to scale AC on HD. AC = 14+HD. So a less than 1HD creature has an AC of 14 while a 1 HD has a base AC of 15, 2 HD at 16. Those with +1 or 2 to hit dice may add that total to their AC, indicating better armor or tactics.
Other Defenses: Assume that the AC is the same value of the other defenses, fort, reflex and will. This might make the monster tougher but its fighting capabilities will be limited as shown below.
Hit points: Hit points listed +20. That's it. Monsters in AD&D already use d8 for hit points. However, NPC characters such as magic users will have considerably less hit points. Consider doubling their hit points and then adding the 20.
Attacks: Attacks are whatever is listed with a 5+HD for attack. If there is a+1,2 etc next to the Hit Dice then add amount to the attack die. So a HD of 1+1 would be a +7 to attack. All attacks are against AC. If the creature has a spell like power or breath weapon it goes against the the appropriate defense (charms psychic vs will, fire and lightning reflex, cold and poison fortitude etc.). For creatures with multiple attacks they gain only up to 3 attacks. If they have more, consider making their attack a burst or blast.
Damage = As listed and I suggest adding 1 to the damage per HD. If they have a + or on Hit die, add that as well. For multiple attacks use either of the highest damage. If the monster is listed with no damage or weapons assigned, then assume some weapon that does a d6. Always give your monsters a ranged weapon as well, in case you need to make them more artillery than grunt.
Special Attacks: Use appropriate condition : for paralyzation use immobilization, for poison use ongoing damage, etc.. Everything is save ends. Those effects that are special because of class, like back stab, would become sneak attack +1d6, surprise bonus (to become and not to be) would be an as he feat Alertness (+2 initiative, may act on surprise round).For certain attacks, such as breath weapon, assume the power recharges 1 die per 4 levels (so a 8th level creature recharges on a 5 or 6) All breath weapons recharge when a creature becomes bloodied.
Size: Some creatures may not list size but usually they will be S small M medium L Large. If they are large, assume they have a threatening reach of Melee 2. If huge, a threatening Melee 3, etc.
Vulnerabilities: If the creature is listed with vulnerabilities it takes the extra damage of 5 for heroic tier and 10 for higher unless is traditionally takes much more (I.e. an ice toad against fire).
Immunities: If the creature has immunity it is treated as having resistance 25 if that would normally cause damage (I.e. immune to fire).
Other Defenses: A common defense in AD&D was the need for magic weapons to do dmage to a creature. The Magic weapons only or +1 or better imply a creature with a tougher build or magical in nature (like an elemental or ghost). Another also included silvered weapons to damage the creature. D&D 3E dealt with this with DR but removed it in 4e. In some cases, regeneration was put in place in the creature to simulate the effect of normal weapons having less effect on a creature. The simplest thing is to ignore it or grant vulnerabilities to the monster against those effects rather than trying to recreate the entire mechanic. Assume the monsters take ½ damage from non qualifying weapons. Assume a dead troll needs to be burned in order to not regenerate and other fluff.
Magic Resistance: In AD&D, some monsters were resistant to magic and spells would not work against them. If the creature has Magic Resistance, consider it having an ability to shake off an effect. Every 15% indicates the recharge on the power. For example, a 30% magic resistance would recharge on a 5 or 6. Magic resistance above 60% will assume the creature can do this at the end of its next turn.
Spells: All spells are treated as encounter powers, including those cast from scrolls. They are attacks as previously stated. In addition, the spells do damage as 2d8+HD for levels 1-5, 3d8+HD for level 6-10 4d8+HD for levels 11+ of the appropriate type unless damage is already figured in. All spells are either ranged burst, area or blast depending on description. If the same power is listed as in 4e, use its traits for it ;for example Magic missile targets single creatures and automatically hits. Range of the spell is 5' x HD of monster; areas are 1 square every 2 HD. All damage dealing spells will require a standard action.
Buff spells will be assumed cast or as immediate interrupts or reactions or minor actions. Such spells give a +2 to +4 bonus to defenses, skill, checks ability checks, damage or attacks. They will last for turn or encounter, depending on description (for example, a bless spell would last for the end of the encounter while a shield spell would last only 1 turn. Healing spells will heal 10 hit points only per tier.
Movement spells will be consider move actions to cast. They last until the beginning of the next turn.
Other spells which deal no damage or serve a utility function, will be cast as minor actions.
Equipment: Usually, you can ignore equipment but in some cases, a AD&D monsters may be gaining the benefit of a magic item. In those cases, assume the item is a part of the creature's powers and not because of an item. If the creature has a +1 Flame tongue sword, assume it has a flaming weapon but is part of the creatures powers. A ring of invisibility becomes another of the creatures powers and not a real ring of invisibility item.
Skill checks: Depending on the creature's nature, it may need to make skill checks or ability checks. Ability checks are at HD while skill checks on things the creature may be good at are made at HD+5. So a ¼ HD kolbold would be at ability checks and non trained skill checks at +1 while a skill they would know, like stealth, would be at +6. When in doubt, assume the creature is trained in the skill. Add any hit die modifier (ex HD 1+1) in addition.
Creating Elites and solos: In 1e, a single monster would usually be a challenge to a party. In 4e, not so much. In the cases of adventures, try to combine multiple rooms/encounters together to make it an interesting fight. If not possible, they simply use one of these to make the creature(s) into solos or elites.
Make an elite: Elites count as two creatures. Double the Hit points . Elites also get +2 to saves. Make dragons, important NPCs, and tough monsters into elites.
Make a Solo: A Solo counts as 5 creatures. Quadruple the hit points. Allow the creature two standard actions, +5 to saves, and when it first bloodies it can make a free attack or reuse any encounter power* as an immediate reaction. Make single dragon encounters or other creatures into solos.
Make a minion: Usually, you may find a group of creatures even in mass number provide no real threat to the PC. You might want to consider them minions. Treat a minion as a normal creature but make its attack bonus 5+ the level of the party and doing max damage. Keep AC the same and use the minion rules of 1 hit point. Four Minions are equivalent to 1 normal monster. Make under a 1 hit die monsters in higher adventurer modules into minions.
Hazards: When ever a hazard appears it attacks the appropriate defense at 5+ Party level and does damage as listed or 2d8+level of party 1-5 or 3d8+ level of party 6-10 etc.
Finally, based on the stats you are ready to re-stat a creature on the fly for the game (see Next post)
five kobolds (AC 7, HD ½, hp 4,4,3,2,1, #AT 1, D 1-4, MV 60 (20), Save NM, ML 6)
the entry would be interpreted: five Kolbolds (Level 1) INT +5 AC 14 Hp 24,24,23,22,21 Daggers +5 vs AC 1d4 Spd 4(squares)
Goblin (AC 6 HD 1-1 Hp 6 #AT 1, D 1-6, MV 60' )
would be read Goblin (Level 1) INT +4 AC 14 Hp 16 Shortsword +5 vs AC 1d6-1 Spd 4
Orc (AC 6 HD 1 Hp 6 #AT 1, D 2-9 MV 9)
would be read: Orc (Level 1) INT +7 AC 15 Hp 26 Mace +6 vs AC 1d8+1 Spd 5
Hobgoblin (AC 5 HD 1+1 hp 8 #AT 1 D 1-8, MV 90')
would be read: Hobgoblin (Level 1) INT +7 AC 16 Hp 28 Longsword +7 vs AC 1d8+1 Spd 5
Ogre AC 4 HD 4+1 Hp 22 D 1-10 MV 6
Would read: Ogre (Level 4) INT +6AC 20 Hp 42 Club +10 vs AC;1d10+5 Spd 4
Black Widow Spider: AC 6; HD 3:; hp 20; MV 60(20); #AT 1; D 2d6 + poison
would read: Black Widow Spider (Level 3): INT +6 AC 18 hp 40; Bite +8 vs AC 2d6 +3 damage and target takes ongoing 5 poison damage (save ends); Spd 4
Merdiz, Human Magician: AC 8; M4; hp 9; MV 120(40); #AT 1; D Unarmed; Save
M4; ML 10; AL N; XP 50 Spells: First Level: sleep, light Second Level: web, wizard lock
would read: Merdiz, Human Magician (Level 4): INT +8 AC 19; hp 38; Staff +9 vs AC 1d6+4; Spd 8 Encounters: sleep Ranged 20' Area 4; +9 vs Will, 2d8+4 Psychic Targets fall unconscious (save ends); light ranged +9 vs Reflex 2d8+4 and target is blinded (save ends) Web; Ranged area 4 +9 vs reflex 2d8+4 poison targets are immobilized (save ends); area is difficult terrain. Wizard lock Range 20' door is sealed DC 25 to break.
Black Panther: AC 4; HD 4; hp 14; MV 210(70); #AT 3; D ld4/ld4/ld8;
would read: Black Panther (Level 4): INT +12 AC 19; hp 34; 2 Claws +9 vs AC ld4+4; Bite +9 vs AC ld8+4; Spd 10
Green Dragon AC 1 HD 8 Hp 48 MV 90(30) Fly 240 (80 ) breath AT 3 + ld6/ld6/3d8 240 SA breath wpn* (Dragons in 1e did their hit point total damage in breath weapons and could use them 3/day).
would read: Elite Green Dragon (Level 8) INT +7 AC 23 Hp 136 Spd 5 Fly 10; (2) Claws +13 vs AC ld6+8; Bite +13 vs AC 3d8+8 Breath Weapon Blast 8; +13 vs Fortitude 2d8+8 damage and ongoing 5 poison (save ends) Miss ½ damage; +2 saves