Proper Leveled Zombies

Level 8 Zombies approach the player in the woods.

I initially set out to do some refactoring and re-introduce Fog Ghouls to the commonwealth after deprecating the Far Harbor plugin to Zombie Walkers. I ended up reworking the entire zombie leveling scheme hopefully for the better.

The Old Way

The old zombie leveling scheme basically matched the game's built in approach for Feral Ghouls. There are eight (8) main base types of Feral Ghouls each at a different level with different stats. These 8 types are combined in leveled list and the version that spawns is highest level Feral Ghoul that is at or under the player's current level. Below is a table of the main stats I'll be focusing on:

Level	XP	Damage Resist	Energy Resist	Base Damage*	Health
1 - 8	7	10	20	30	35
9 - 14	13	15	30	45	70
15 - 21	22	30	45	60	80
22 - 31	32	40	60	70	140
32 - 41	47	50	75	80	170
42 - 51	61	60	90	95	200
52 - 61	76	70	110	105	385
62+	90	85	140	120	505+

*note: Base Damage was increased by 15 over base game and extra radiation damage removed. The value listed is damage done on Normal difficulty (2x = very hard, 4x = survival).

A couple things to note from the above:

• Health increases greatly at level 52 and again at level 62. After 62, the zombie health can and does continue to grow as the level 62 variant of Feral Ghoul is the only one that levels with the player.
• Base Damage on survival is lethal. At level 1, zombies do 30 * 4 = 120 damage which is enough to one shot many characters. Survival is the difficulty this mod is meant to be played at, but zombies one shotting players isn't what I am going for either.
• Between level jumps, the zombie stats remain static. This means a level 8 zombie is identical to a level 3.

The New Way

I used the Google Chart API to graph the progression of these statistic changes for Feral Ghouls and noticed that most fit a linear trend. The API allows charts to render trend-lines that provide the formulas which I extracted and used in the OnInit method of the zombie's script to set there stats after they spawn. Here are screenshots of the charts (just in case the API changes, I don't want to have to maintain them here):

XP = 1.432 * Level + 1.063

Damage Resist = 1.24 * Level + 8.276
Energy Resist = 1.933 * Level + 13.988

Damage =  1.433 * Level + 33.175

Health = 5 * Level + 20

A quick note about the Health chart. Notice the two red dots above the trend line toward the right. Feral Ghouls gain more health at levels 52 and 62 than they normally do prior to that. It seems like an attempt by the game creators to just make them a lot tougher for high level characters to face. To create this trendline, I basically used the 35 health at level 3 as a base and extrapolated it out using the game's known health leveling formula. Coincidentally, all of the other Health totals fell in line with this trend.

Survival Damage Adjustment

The new way actually increases damage dealt at level 1 to about 35. On survival this becomes 140! To address this, I added a new holotape option that allows players to adjust the amount of damage done on survival and set the default to match very hard (2x) so that level 1 damage is 70 which should be survivable (at least 1 hit anyway).

To implement this so that it only affects zombies, I actually divide the damage they do by an amount to where when it is multiplied by 4 (survival's damage mult) it comes out to the value I want. For example: diving 35 by 2 gives 17.5, which when multiplied by 4 becomes 70.

Refactoring Spawn Variety

To initially implement spawn variety, I created copies of the 8 actor types for each level increment and manually adjusted their stats at each level. Tedious, painful, and a maintenance nightmare. Not to mention having 8 * 8 = 64 zombie actors increased the size of the mod.

To refactor, I deleted all the extras and stuck with the base 8 types. All of their stats are set via a script attached to them when they spawn now, so I no longer have to worry about manually setting their stats via the GUI. 

I also went through and added all available skin tones for Feral Ghouls in the base game to all variations (Traits -> Object Template on the Actor in CK) and added the special Pink zombies from Suffolk County Charter School for fun.

  4 different base outfits (default, bloody, withered, armored)
* 7 different base skins (Carrion, Charr, Dark, Green, Grey, Pale, Pink)
= 28 base combinations
+ 1 special Suffolk Country Charter School skin/outfit
+ 1 Fog Ghoul skin/outfit (if Far Harbor installed, see below)
= 30 total combinations

Fog Ghouls Zombies

Finally, I added the necessary code to add the Fog Zombies to the commonwealth if you have Far Harbor installed. Originally, I was just going to add the outfit to the list above, but I thought it would be funner and maybe more appropriate to use these zombies to replace marine creatures (if spawn replacements are used). In this way, when you enter an area that would spawn things like Mirelurks, which are normally near water, you would start to see the fishing net covered Fog Zombies.

Here's the list of creature types replaced by Fog Zombies (if replacements are enabled):

• Creatures
• Anglers
• Gulpers
• Mirelurks
• Heavy Knockers
• Fog Crawlers
• Hermit Crabs

Zombie Walkers 2.0

The above was released as part of the Zombie Walkers 2.0 release. Since the leveling changes and refactoring was quite large and affected the core of the mod, I decided to finally up the major version number. I'm hoping to stick with a more canonical versioning scheme moving forward.

Other changes included in this release was a fix for immortal zombies caused by explosive damage and a reset of the Far Harbor leveled lists to help those migrating away from that deprecated mod.