Hey all, First, I want to thank @Victor for creating this. Thank you for your time and effort spent into this. I'm spending a lot of time working on things to make it work great for the players in my campaign—as a non-programmer who is barely able to understand how these types of things work, I can't imagine how much comparative time you've spent and are continuing to spend building and maintaining such a complicated beast. Second, I'll note that I've read everything in this thread, lightly glossing over things that were very specific or redundant (the nth instance where an individual had a similar question as before—not insulting them, just a funny observation). That being said, I've gotten fixated on one thing, and although I know @Victor has said "no more changes, only maintenance," I figured I'd post about it in case he (or another) mercifully helps me: Concentration! I know there isn't an official implementation or support for them, but I have been using the user-made APIs posted in the thread. There were two that I saw here; one by @KeithCurtis and a later one by @VictorB. I also saw @Persephone engaging in the comments about them and testing them. Keith's script ( KeithCurtis CON roll20forum - scroll down a bit until you find the code) short, sweet, and to the point. It does dutifully detect if a token has the appropriate "concentration" marker (delineated by CombatMaster), and whispers the GM when said creature receives damage, automatically calculating the CON save DC per D&D5e rules. I modified it slightly so that it sent said message in chat, rather than as a whisper, so that the player in question could click the button to make the save. Again, this works perfectly at what it is doing, but it doesn't automatically add concentration to tokens when their character sheet clicks off a spell that instills concentration (aka has the {{concentration=1}} field) . This is not an error of Keith's code—it just wasn't the goal of the code. I can account for this, the hard way, by just adding a token-mod script to every spell in the game on every character sheet I'm using, but that's obviously a tedious task for something that just amounts to "hey, dummy, remember to click the button"—hence my desire to find a way to filter by the {{concentration=1}} field and automate this. Victor's script ( VictorB CON github ) This one is so daunting that I'm at a loss as to where to even begin to make the tweak(s) I'm interested in taking care of. This script beautifully checks if a spell is cast with a {{concentration=1}} field, and then automatically marks said token and outputs a little notification to chat! I'm completely happy with that—works as intended. However, when said script was initially posted into this thread, @persephone rightly pointed out that, despite seeming to have code trying to detect if a token is damaged, the script doesn't seem to follow through and accomplish anything when the creature receives damage. So, TL;DR I'm wondering if there is any chance anyone could help me with any of the following questions: Is there any chance I could just change a couple lines of code in Victor's script to get it up and running? If so, could someone help me solve that? Or even point me in the direction of resources that could allow me to solve that on my own? This is . . . javascript? Right? I don't even know where to get started. If not, is there any way I could cut the parts currently not working such as to avoid any API clashes, and thereafter just use KeithCurtis' script and a fragment of VictorB's? Am I overthinking things? Will they just "play nice" to begin with? (obviously trial-and-error would elucidate this) Like I said, I have no clue with this stuff. Would anyone likeminded but far more skilled with API be willing to undertake this crusade and get VictorB's CON script (linked above) troubleshooted*? Or maybe the problem exists between keyboard and chair and they can help me solve that, alternatively. *as an aside, is the past tense of "troubleshoot" . . . "trouble shot" ??