» Sun Jan 31, 2016 6:35 am I have posted this before but it is such a popular topic I will post it here in it's own thread.
The defense must be = food + water theory is a myth.
For every 1 point in defence you can safely produce 10 food or water.
2 settlers is equal to having 1 additional defence point. Read on.
Someone on reddit decompiled the script that determines settlement attacks. This is the what was determined from the code:
1) You need at least 1 settler to trigger attacks. Settlements with 0 settlers will never be attacked.
2) A single settlement cannot be attacked more than once every 7 days.
3) Every settlement with at least 1 settler has a base chance of 2% to be attacked daily. This cannot be lowered below 2%.
4) For every unit of food or water a settlement produces, it increases attack chance by a tenth of one percent. So for every 10 food or water your settlement produces, your chance of being attacked increases by 1%. Resources stored in your workbench DO count towards this formula!
5) There are two ways to reduce your chance of a settlement being attacked. Defences and settlers.
- Every 1 point of defence reduces your attack chance by 1%. (or for example, 1 defence for every 10 food or water).
- Every settler reduces your attack chance by a half of 1%. (or for example, 1 settler for every 5 food or water).
So what does this all mean? Examples:
Settlement #1 produces 50 units of food and also 50 units of water. It has 10 settlers and 0 defence. Therefore, it has a 7% chance of being attacked per day. Formula: 2% base + (50 food +50 water) /10% = 12% attack chance. Each settler reduces attack chance by .5% so that is a reduction of 5%, bringing down the chance of the settlement being attacked to 7% daily. To reduce the attack chance to the minimum 2% you would only need 5 units of defence (or 10 more settlers).
Settlement #2 is exactly the same except that there are 500 units of purified water stored in the workbench. Those 500 waters alone increase your attack chance by 50%. You would need an additional 50 units of defence if you plan to keep those waters in the bench indefinitely.
Settlement #3 is a water farm that produces 1000 water, 0 food, and has 1 settler. It has a 101.5% chance of being attacked daily. You would need basically 100 units of defence to reduce it to the minimum 2% attack chance.
Mind you, if you kill of that settler you would never get attacked anyways.
So basically, one unit of defence per 10 units of food or water is all you need. Anything more just helps you kill attackers faster (as long as you show up). If you don 't show, it doesn't matter if your generators are walled in or you have 5000 turrets, you will end up with lots of broken junk.
Raid Strength:
Types of mobs and their strength are determined by how many resources you produce (strength) and your character level and advancement in the main questline (type). For example, I have yet to have a synth infiltrator attack in a settlement because I have not discovered the synths in the main questline yet (faction quests dont count).
Raid Strength formula:
