What they need to do in the descriptions of upgrading traits is something like this:

Shadow Strike I: Ignores 25% of the victim's defense.

Shadow Strike II: Ignores 25% (50% total) of the victim's defense.

Shadow Strike II: Ignores 20% (75% total) of the victim's defense.

This would clear up a lot of confusion.

Derek, any chance this might make it into the .9 release? Seems like an easy fix and would clarify what's happening.

Yes, the current system is counter-intuitive.  It wouldn't take much to fix.  I could do it myself.  Probably an hour in the XML. 

From the way it's worded, it should cap at 100%.  Can't ignore more armor than there is.  That said, who knows how they're doing the math?  

The issue is that the traits are shown in different areas.  You can see them in the trait tree, and you can see them in the unit screen.  In the unit info window they are rolled up so you only see the highest level one.  In the trait tree you can view them all.

In the trait tree it is ideal to see "Ignores 25% of the victim's defense"

In the unit pane its ideal to see "Ignores a total of 75% of a victims defense"

Either way we switch it isn't ideal in the other case.  The possible solutions for this are:

1. Keep it as is (which can be confusing understanding exactly what the traits do in the unit screen.

2. Extend the descriptions as Mqpiffle suggests "Ignores 20% (75% total) of the victim's defense" which could be confusing in the trait tree (for casual players who havent read this thread and understand what it is trying to tell them).

3. Dont have these sorts of traits hide when upgraded.  Show all 3 levels of shadow strike 1, 2 and 3 on the unit screen.

Im leaning toward option 3 as the most clear depiction of what is happening.  What do you guys think?

ps: you cant ignore more than 100% of a victims defense, 100% armor piercing and 300% armor piercing are the same thing.

the community suggestions thread also contains that item

my suggestion was to either do, basically what was suggested above, say

"Lethal III - increases attack by +5, cumulative with Letahl I and II for a combined value of +12"

or change the way they are represented on the character sheet and redo the text:

"Lethal III - adds +12 attack, replaces Lethal I and Lethal II"

in my opinion, the second way is better (iirc Blizzard used a similar style in WoW when i played that game - and they probably spend more money on making their games idiot proof than most indie devs spend on their whole game)

I think this would be the least confusing.

But having them visible also satisfies other side of customers, those who love details and to see every bit of info they can get etc

I prefer this version of the tooltip. The behind-the-scenes mechanic doesn't matter so much, since whether Lethal III grants +X attack and stacks with Lethal I and Lethal II for a total of +Y attack or Lethal III grants +Y attack and replaced the bonus from Lethal II which replaced the bonus from Lethal I doesn't really matter to me, unless I'm trying to create a mod, but details like that are what a modder's guide or comments in the visible parts of the code are for.

Plus, I don't want to have to search through 10 or 15 traits to try to find out what a champion has, since that just makes a mess out of the trait list in the unit details screen, which is already a bit cumbersome to use.

I like the "replaces" option Azunai_ suggested best.  In most games, when you have multi-leveled traits like this, the higher level one replaces the lower level ones, and its description includes the stats from them.  I was assuming that was how this game worked until someone said otherwise and I tested it.  I had thought that Potential II and III were just really bad.  Therefore, rolling up the stats into each subsequent trait is the best option, but also noting that it replaces the prior trait so there is no question about how it works.

Listing out all the traits would add a lot of unnecessary clutter, and still wouldn't absolutely remove any question about how it worked.  People might think it was a bug that the prior traits were still showing.

Option 3 can lead to a rather cluttered screen, I do like the condenced look.

Option 2 can be confusing for casual players, but alieviates the clutter.

Option 1 is what it is, confusing.

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Option 4 -- Ignores 20% of the victim's defense. Stacks with shadow strike 1 and shadow strike 2.

This will not cause the confusion in option 2, but then these descriptions get rather long, but is clear. This will inform the player that this is a stacking bonus and indicates the traits it is stacking with.

Option 5 -- Ignores 20% more of the victim's defense.

The more gives the indication that it is a stacking bonus.