Alright, so to preface this: I'm still learning code. Which shouldn't be surprising given the post to follow, and makes it difficult for me to express what I'm looking for in the correct terminology. I've been slowly learning but feel that what I want to accomplish is simple enough that it may be easier to seek advice here. That being said, I know the answer can likely be boiled down to needing further education on the matter. Basically I want to use a number value to calculate another, which is 10% of that first number. So I have a homebrew, and it's a relatively math-heavy system. Players have to balance three sources of energy to survive and perform actions/cast spells: health, magic, and stamina. I have them coded like this: <div class="col"> <h2>Life Stats</h2> <div class="stats"> <h3>Current</h3><h3>Max</h3> <label>Health</label><input type="number" name="attr_health" /><input type="number" name="attr_health_max" /> <label>Magicka</label><input type="number" name="attr_magicka" /><input type="number" name="attr_magicka_max" /> <label>Stamina</label><input type="number" name="attr_stamina" /><input type="number" name="attr_stamina_max" /> </div> </div> Next I have the rate at which they recover at the end of each round of combat, determined by the maximum of each value. <div class="col"> <h2>Regen Rate</h2> <div class="stats"> <label>HR</label><input type="number" name="attr_healthrate"/> <label>MR</label><input type="number" name="attr_magickarate"/> <label>SR</label><input type="number" name="attr_staminarate"/> </div> </div> Finally, I tried to make a simple sheet worker script which takes the maximum values of each to calculate and input the regen rates. <script type="text/worker"> on(“change:health_max change:magicka_max change:stamina_max sheet:opened”, function() { getAttrs([“health_max”,”magicka_max”,”stamina_max”], function(values) { let health_max = parsInt(values.health_max,10)||0; let magicka_max = parsInt(values.magicka_max,10)||0; let stamina_max = parsInt(values.stamina_max,10)||0; let hr = health_max * 0.1 let mr = magicka_max * 0.1 let sr = stamina_max * 0.1 setAttrs({ hr: healthrate, mr: magickarate, sr: staminarate }); }); }); </script> And it doesn't... really do anything. So far my thoughts are that either I haven't specified an output location or perhaps the way I named each attribute doesn't work. Is this something that can be done with a sheet worker script or do I need some sort of auto-calc script? I've tried looking through other coding examples and am still not sure what I'm missing here. Update: Note sure if this is related to the API issues that are currently outstanding. Looking into it, though.