sv mark generation lua function

sv_mark.lua

-- Time
local Time_DayDawn      = 0
local Time_Dusk         = 1
local Time_Night        = 2

-- Weather
local Weather_None      = 0
local Weather_Cloudy    = 1
local Weather_Rainy     = 2
local Weather_Stormy    = 3
local Weather_Snowy     = 4
local Weather_Blizzard  = 5
local Weather_Dry       = 6
local Weather_Sandstorm = 7
local Weather_Misty     = 8

-- Marks
local Mark_Lunchtime    = 53
local Mark_SleepyTime   = 54
local Mark_Dusk         = 55
local Mark_Dawn         = 56
local Mark_Cloudy       = 57
local Mark_Rainy        = 58
local Mark_Stormy       = 59
local Mark_Snowy        = 60
local Mark_Blizzard     = 61
local Mark_Dry          = 62
local Mark_Sandstorm    = 63
local Mark_Misty        = 64
local Mark_Destiny      = 65
local Mark_Fishing      = 66
local Mark_Curry        = 67
local Mark_Uncommon     = 68
local Mark_Rare         = 69
local Mark_Rowdy        = 70
local Mark_AbsentMinded = 71
local Mark_Jittery      = 72
local Mark_Excited      = 73
local Mark_Charismatic  = 74
local Mark_Calmness     = 75
local Mark_Intense      = 76
local Mark_ZonedOut     = 77
local Mark_Joyful       = 78
local Mark_Angry        = 79
local Mark_Smiley       = 80
local Mark_Teary        = 81
local Mark_Upbeat       = 82
local Mark_Peeved       = 83
local Mark_Intellectual = 84
local Mark_Ferocious    = 85
local Mark_Crafty       = 86
local Mark_Scowling     = 87
local Mark_Kindly       = 88
local Mark_Flustered    = 89
local Mark_PumpedUp     = 90
local Mark_ZeroEnergy   = 91
local Mark_Prideful     = 92
local Mark_Unsure       = 93
local Mark_Humble       = 94
local Mark_Thorny       = 95
local Mark_Vigor        = 96
local Mark_Slump        = 97
local Mark_None         = -1

function LotRibbon(arg0)
  local rand_val, weather, time_period, current_hour
  -- fDAAAA586 appears to be some form of rand(minimum, maximum) of [minimum, maximum]
  rand_val = arg0.fDAAAA586(0, 999)
  -- 1/1000
  if 0 == rand_val then
    return Mark_Rare
  -- 10/1000
  elseif rand_val >= 1 and rand_val <= 10 then
    -- random personality mark
    -- 1/28 per
    return 70 + arg0.fDAAAA586(0, 27)
  -- 20/1000
  elseif rand_val >= 11 and rand_val <= 30 then
    return Mark_Uncommon
  -- 40/1000
  elseif rand_val >= 31 and rand_val <= 70 then
    if C2B428A63695FD2C7.CheckBirthday() then
      return Mark_Destiny
    end
  -- 20/1000
  elseif rand_val >= 71 and rand_val <= 90 then
    weather = main.env.weather.WeatherManager.s_impl[5].type
    if Weather_Cloudy == weather then
      return Mark_Cloudy
    elseif Weather_Rainy == weather then
      return Mark_Rainy
    elseif Weather_Stormy == weather then
      return Mark_Stormy
    elseif Weather_Snowy == weather then
      return Mark_Snowy
    elseif Weather_Blizzard == weather then
      return Mark_Blizzard
    elseif Weather_Sandstorm == weather then
      return Mark_Sandstorm
    elseif Weather_Misty == weather then
      return Mark_Misty
    end
  -- 20/1000
  elseif rand_val >= 91 and rand_val <= 110 then
    time_period = main.system.game_time.GameTimeManager.s_impl.F36837B48B38D4857(
      main.system.game_time.GameTimeManager.s_impl,
      main.system.game_time.GameTimeManager.s_impl[5].gameTime
    )
    if time_period == Time_DayDawn then
      function getSecondInDay()
        local current_second
        current_second = nil
        if main.system.game_time.GameTimeManager.s_impl[5] ~= main.system.game_time.GameTimeManager.s_impl[4] then
          current_second = main.system.game_time.GameTimeManager.s_impl[5].gameTime
        else
          current_second = main.system.game_time.GameTimeManager.s_impl.F8C8B225CB8805704(
            main.system.game_time.GameTimeManager.s_impl,
            main.system.game_time.GameTimeManager.s_impl[5].gameTime
          )
        end
        return current_second
      end
      current_hour = getSecondInDay() / 3600
      if current_hour >= 12 and current_hour < 18 then
        return Mark_Lunchtime
      else
        return Mark_Dawn
      end
    elseif time_period == Time_Dusk then
      return Mark_Dusk
    elseif time_period == Time_Night then
      return Mark_SleepyTime
    end
  end
  return Mark_None
end

The game always rolls a single rand(0, 999) (inclusive)

• if rand == 0 (always 1/1000 odds) the mon has a rare mark
• if rand is in the range [1, 10] (inclusive, always 10/1000, 1/100) the mon has a personality mark
  • the game will then roll a rand(0, 27) (inclusive) to determine which of the 28 personality marks it gets
• if rand is in the range [11, 30] (inclusive, always 20/1000, 1/50) the mon has an uncommon mark
• if rand is in the range [31, 70] (inclusive, always 40/1000, 1/25) the mon is susceptible to having a destiny mark
  • the destiny mark will only be applied if it is the player's birthday, otherwise no mark at all will be applied
• if rand is in the range [71, 90] (inclusive, always 20/1000, 1/50) the mon is susceptible to having a weather mark
  • the game checks for Cloudy, Rainy, Stormy, Snowy, Blizzard, Sandstorm, and Misty weather in that order to give the corresponding marks
  • if there is no weather no mark is applied
  • see other research for which weathers are actually legal in-game as I do not know crowd-sourced weather sheet provided by Anubis (@Lusamine)
• if rand is in the range [91, 110] (inclusive, always 20/1000, 1/50) the mon is susceptible to having a time mark
  • the game checks for 12 <= current 24-hour clock hour < 18 for Lunchtime
  • Dusk/SleepyTime/Dawn have their own way of checking time that was not immediately obvious which time period they apply to, probably the same as swsh

I am unsure if Mark Charm has an effect (if so it would very likely just be repeating this entire roll system up to 3 times or until a mark is selected) but it is not legitimately obtainable in SV anyway.

These odds are very slightly different than SWSH as SWSH had consecutive rolls for each mark type, skipping the rest of the rolls if a mark is chosen.

Easy to read table containing this rate information as well as when the title powers are applied courtesy of Anubis:

https://mobile.twitter.com/Sibuna_Switch/status/1625345500869271553