So basically I've been trying to build my settlements. Well to be honest just the castle and sanctuary. However, I'm to this point where no matter what I do I can't send more people to sanctuary. Is there a reason behind that? I've check beds food defense, I got it all out the wazoo. But I can't send people to sanctuary. Is it full maybe? Can it only hold 19 people because that's where it's at right now.

The settlement population is based on the formula 10+charisma. If you have a base charisma of 6, this means that you can, in theory, only have 16 settlers there. You can wear charisma boosting clothing and take charisma boosting chems while you're in a given settlement to increase the population limit. While under the influence of this charisma boost, the population limit will be higher.

Max # of settlers equals your charisma plus ten. You can boost your charisma with clothing and/or chems, then you can have more settlers.

Yep, clothing and chems can boost your Charisma so that you can have lot's of settlers in one place.

The max number of settlers you can have is at least 31. There is a wandering level 4 weapon trader that you convince to join your settlement that will turn a level 3 weapon shop into a level 4 weapon shop. But you will not have that option until you have 30 settlers in one settlement.

If you are playing on the PC, then I am sure there is a mod out there that will remove population restrictions. The more settlers there are the more CPU processing power you will need.

http://www.nexusmods.com/fallout4/?

Just want to point out of some of the caveats. If you lose the effects of your charisma-boosting chems and/or clothing, you will also lose your population cap. That means it is possible that your settlement's population is actually HIGHER than your charisma plus 10 after you lose the charisma boost. And that you means you CAN ONLY SEND AWAY settlers, but not get any. You have to keep sending away settlers until your population is lowered to charisma + 10 or less before you can add settlers.

Here: https://www.reddit.com/r/falloutsettlements/comments/405lk9/psa_settler_recruitment_and_raid_chances/

Some of the things in this post seem to make sense, but some still don't. It says chance of getting settlers is 10 plus half of happiness. I have many settlements with 15-20 settlers and 80-85 happiness, which should give me 50-53% chance. Yet, some have gone weeks and months without getting new settlers.

The part about 2% chance of getting attacks for each settlement is rather misleading. If you have 20 settlements, and each has 2% chance, that means the chance of ANY settlement getting attacked is 20 x 2% = 40%. That explains why many of us see attacks happening daily.

I have 26 settlements all except the castle has defense higher than water+food but many just a bit higher.

Been weeks since the last settlement attack. Has an mod who gives an pop up message I have to click if I get an attack so I can not miss it.

Castle has only been hit twice, has been a few other times but no settlement attakk message so probably random encounters or caravans pulling enemies into the fire zone.

300 water/ day+230 in workbench+ probably 1000 food as I store all raw food I gather there.

150 defence and 25 population.

Bunker hill with 8 population 9 food and water and 100 defense has been hit twice and is an new settlement after the main quest.

no the number of settler requirements for the level 4 vendors (that have one) is TOTAL population, not population in single settlement

the only caveat to that is to count towards population the settlements must be linked by supply lines

eg smiling larry requires 30 total population

so if they were linked by supply lines the 10 settlers at sanc + 8 settlers at abernathy + 8 settlers at greygarden + 4 settlers at tenpines = 30 and yopu would be able to hire him.

although almost all level 4 vendors are bugged and dont work anyway

the radio beacon can become bugged, for those settlements that you arent getting settlers to, go to that settlement and see if the settler recruitment station is available under radio.

quite often the radio beacon can be on but not broadcasting so just switch her on and off and it seems to work again.

i aslo had mine bug out at greygarden one time where it wouldnt broadcast so i went to do that but after switching off it would not swith on again just stayed in off.

stored it and re placed it, that fixed it.

"(note that food and water items in your workshop inventory count towards these totals. Thanks to https://www.reddit.com/u/matzman666 for pointing that out.)"

Well, that might explain a few things on my last play through.

I need to correct my math. That posts says a settlement can't be attacked more than once every 7 days. So for 20 settlements, the probability of any settlement getting attacked in any day is not 40%, but only 28%. This is because we have to assume 6 settlements have been attacked in the 6 previous days. So the ongoing probability is only 40% - 6 x 2% = 28%, about 1/4. So if you have 20 settlements, expect an attack once every 4 days. That seems to be my experience.

Of course, if you're unlucky, the attacks bunch up. The probability of an attack anywhere in N consecutive days = 1/4 ^ N.

N=2, P=1/16

N=3, P=1/64

N=4, P=1/256

N=5, P=1/1024

N=6, P=1/4096

N=7, P=1/16384.

So the chance of attack(s) happening daily is only 1/16384.

The probability of having two settlements getting attacked simultaneously (which has happened to me twice in 400+ hours) is, of course, very small. For one attack to happen in a particular hour (out of 24 hours), the chance is 1/4 x 1/24 = 1/96. The chance of two of them in the same hour = 1/96 x 1/96 = 1/9216.

Of course, this all depends on how many times the game "rolls the dice". The post says it is done daily, which we assume is once daily. But if the dice are thrown more than once in a day, all the probabilities improve, of course.

Have to correct my math yet again. The 1/4 attack chance does not mean you will be attacked "once in 4 days". It only means 1/4 chance in ONE day. By saying an attack will occur once in 4 days, I'm suggesting the chance of an attack in a 4-day period is 1/4+1/4+1/4+1/4 = 100%, which is, of course, not true.

The chance of an attack happening in any 4-day period is calculated as below:

Chance of attack in day 1, but not in day 2-4 = 1/4 x 3/4 x 3/4 x 3/4 = 27/256.

Chance of attack in day 2, but not in day 1, 3, and 4 = 1/4 x 3/4 x 3/4 x 3/4 = 27/256.

Chance of attack in day 3, but not in day 1, 2, and 4 = 1/4 x 3/4 x 3/4 x 3/4 = 27/256.

Chance of attack in day 4, but not in day 1, 2, and 3 = 1/4 x 3/4 x 3/4 x 3/4 = 27/256.

To get the chance of an attack in ANY day in a 4-day period, you add up the above, which is 108/256 = 42%

The chance of an attack in a 7-day period = 31%

There's some question about how and when settlements run their updates. I haven't been able to get Caprica to recompile the workshop script without throwing casting errors, so I haven't been able to test exactly when / why the daily update will run on a settlement.

Also, quick math correction. 20 settlements at 2% chance each = 1 - ((0.98)^20) = ~33% chance of at least one attack per day. Close. And, yes, that's why you see so many attacks.

EDIT: I see there have been more math corrections. Recalculate as needed.

As has been pointed out in the thread your Charisma level is what limits your population.

What you do is go to the settlement that you want to move settlers from and temporarily boost your charisma.

The game lets you move the settler/settlers then.

I have all the settlements populated.

Most at 24 but some at 33 and some between 24 and 33.

If I meet the dog or cow seller I have to boost my charisma (usually drink beer or another brew) to be able to accept another one.

Some of the temporary boosts stack so you could take a drug plus drink beer whilst wearing the charisma boost clothing to get the cap up.