In Harry Potter: Wizards Unite, the Threat Level Clock is a device that the developers set up to give a visual representation of a Foundable's 'catch' difficulty (for this article it will be known as 'return rate'). However, the clock is more complex than it may appear and interpreting it can be downright misleading.
Threat Level Clock Explanation
The clock consists of five levels and eight sections. The sections are assigned various - extremely uneven - percent ranges. Below is a list of the threat levels, their correlating sections, and the percent ranges assigned to them. (These percentages represent your chance of success.)
Threat Level: Low
Section 1: 100% - 40%
Section 2: 40% - 36.5%
Threat Level: Medium
Section 3: 36.5% - 24%
Section 4: 24% - 21%
Threat Level: High
Section 5: 21% - 10%
Section 6: 10% - 4%
Threat Level: Severe
Section 7: 4% - 1%
Threat Level: Emergency
Section 8: 1% - 0%
Your chance of success drops rapidly, losing over 60% before you even hit the second threat level. This means the two bold hands you see on the clock must be well into the first section of green for you to have over a 50% chance of returning the Foundable. If you want a bit more info, here is a full list of Foundables and their threat levels and success percentages.
The Clock Hands
In total there are three hands on the clock. These represent your possible success range.
Hand 1: The hand closest to 'Emergency' (the red) will be more translucent than the other two. This hand shows the Foundable's base difficulty, or 'return rate'. This is your chance of success without any bonuses applied.
Hand 2: This hand looks the same as 'Hand 1' except that it is opaque and bold. It represents your minimum chance of success or the 'actual success rate' of returning the Foundable (including applied bonuses).
Hand 3: This hand doesn't have an actual hand on it, like the other two, but it is bold like 'Hand 2' and will sit closest to 'Low' (the green) on the Threat Clock. This displays your maximum possible success rate, which comes into play when using Extimulo Potions.
Applicable Bonuses and Equations to Determine Success
The bonuses that affect your actual success rate pertain to your player level and the use of Extimulo Potions. The latter acts as a rate multiplier.
In the game, you are notified every five levels that Foundable encounters will now be easier to overcome. This is due to a level bonus that correlates directly with your level; +5 for levels 5-9, +10 for levels 10-14, +15 for levels 15-19 and so on. Levels one through four, unfortunately, receive no (x1) level bonus. This does NOT change the Foundable's base return rate (Hand 1's position on the clock) but, your actual success rate (Hand 2).
Bonus Success Rate - Equation
We now have the information to understand the first equation in determining the chance of success. This equation will factor into the main equation later on.
Bonus Rate = (0.6 - Return Rate) × level bonus ÷ 180
Extimulo Potions can be administered to directly affect the actual success rate (Hand 2) and the maximum success rate (Hand 3). The potions act as a rate multiplier and seem to have a minimum and maximum bonus that may be applied. Below are the approximate base and maximum values possible for each potion.
Extimulo: ×1.5 (base) - ×2 (max.)
Strong Extimulo: ×2 (base) - ×2.75 (max.)
Potent Extimulo: ×4.25 (base) - ×5 (max.)
It is interesting to note that even without the use of an Extimulo Potion, you have a possible max rate multiplier of 1.5 (the same base value as using a standard Extimulo Potion).
Actual Success Rate - Equation
Now that we have a grasp on all of the factors, the main equation for figuring out your chance of success should seem quite simple. The equation is as follows.
Actual Success Rate = (Return Rate + Bonus Rate) × Rate Multiplier.
There you have it- your actual chance of returning the Foundable. It should be noted, however, that these are relatively preliminary findings and that the Wizards behind the mathematics are rather recently going public with these bits of information. The hands on the clock make more sense now that we understand that they are each assigned a certain value within the scale of success; a good visual representation of the possible to actual success ratio. Another note to make is that Spell trace accuracy does not seem to affect the success rate, but merely acts as an XP multiplier after the Foundable is successfully returned. (This could be a good thing, as some spells are difficult to trace and a Masterful cast seems just about impossible on any of them!)
With such uneven threat level percentages, you may be discouraged in finding out that the Medium level Bludger Foundable you thought had a roughly 70% chance of success, really only has 25%. But, with player level and Extimulo Potions amplifying success, it should encourage you to hit that level grind- and utilize tons of Extimulos along the way, as they boost your actual success rate directly.