Right off the bat, yeah, this has been done before. However, I didn't really want to mess with the radiation system. I use Classic Radiation Poisoning on my survival run, so exposing myself to radiation in order to gain mutations was a fairly dire proposition. With this in mind, I figured, hey, why not just let the player craft serums that have a limited duration and have that be the end of it? Players can pick and choose what they want, when they want, and there won't be any complicated stuff going on. So that's what I did.

At a chemistry station, you can craft a number of mutation serums that will provide you with a buff and a penalty for an hour. I went back and forth on duration, but I ultimately decided an hour would be fine. It's definitely extremely generous, but I didn't want to create a situation where you'd need to craft a bunch of serums and carry them on you during your adventures. Just pop them and forget. I didn't include all of them, since some of them wouldn't translate well to Fallout 4 or just didn't seem worth the effort. Like Empath. I could have set that up to work with companions, but that would have felt like a waste of effort.

When it came to setting up the strength of each buff and penalty, I decided on making them comparable to Strength in Numbers and Class Freak combined. This results in the buffs being quite a bit stronger and the penalties being a lot weaker. That's certainly a lot less balanced, but I can accept that in the name of fun. If there's interest, I could always retool things to be more equal.

Here is a detailed explanation as to what each serum does:

• Adrenal Reaction: Extra damage the lower your health goes (caps at 63% extra damage at 20% HP); max HP is reduced by 13
• Bird Bones: +5 Agility, +50 AP, -95% fall damage; -1 Strength and +5% extra limb damage
• Eagle Eyes: +5 Perception and +75% critical hit damage; -1 Strength
• Egg Head: +8 Intelligence; -1 Strength and -1 Endurance
• Grounded: +125 ER; -12% damage with energy weapons
• Healing Factor: +375% HP regeneration while outside combat; -13% to chem effectiveness
• Herd Mentality: +3 to all SPECIAL while travelling with a companion; -1 to all SPECIAL while travelling alone
• Marsupial: Jump height multiplied by 3.75 and +25 carry weight; -1 Intelligence
• Scaly Skin: +62 DR and ER; max AP is reduced by 13
• Speed Demon: Movement speed is increased by 25% and reload speed is increased by 40%; sprinting costs more AP
• Talons: +31% damage with unarmed weapons and unarmed attacks cause bleed damage; -1 Agility
• Twisted Muscles: +35% damage with melee weapons and +20% chance to cripple enemy limbs; ranged weapon accuracy is reduced by 13%