What criteria determine what is or isn't Uvdin Dechol

Question

I am struggling to understand the concept of Uvdin Dechol, where it originates from and how far it extends to.

We famously dont ride bikes / electric trams on Shabbos partly due to Uvdin Dechol, but many Poskim allow Shabbos lifts, which would seem should also be categorised as Uvdin Dechol.

Even stranger was when I just saw the Magen Avrohom when discussing playing chess on Shabbos, that they used to play with silver pieces so as not to appear like Uvdin Dechol.

I am ideally looking for a thesis that someone has published with guidelines, sources etc clearly defining what it or isn't Uvdin Dechol.

If no such publication is out there, and you have knowledge to share on this, please share all sourceable information that you have.

Answer 1

dinonline writes

The definition [of uvdin de-chol] is somewhat vague, leading to some lack of clarity in this subject.

The based principle is that matters that are related to a melacha, or matters that involve some denigration of the holiness or spirit of the day, are included in the category. Thus, it is forbidden to engage in commerce and to weigh foods, to carry jugs of wine from place to place (in the regular manner), to grind spices with a grinder, and to gather scattered fruit into a bag

see also here

Even if vague, R Tzuriel Ohayon managed to write a 630-page Hebrew sefer on the topic (Uvdin Dechol Beshabbos Veyom Tov). It might be the thesis you are looking for -- although I haven't seen it inside.

Answer 2

I found this article with 28 sources. From his conclusion it appears that the Ramban and Rambam argue on its definition. Here's my loose translation of his conclusion:

The Ramban defines it as a Torah prohibition that destroys the don't do work aspect of Shabbat and Chag and includes those actions that destroy the Restful Character of the day.

המינוח 'עובדין דחול' מופיע בסוגיית הגמרא בשבת וביום טוב כבסיס לאיסור פעולות במועד ובשבת. הראשונים נחלקו בהבנת האיסור: לשיטת הרמב"ן מדובר על איסור תורה הנובע מביטול מצוות העשה של שבתון. דברי הרמב"ן לא הובאו להלכה בספרי הפסיקה, אך במאתיים השנים האחרונות הרחיבו את דבריו כמה פוסקים לכלל המלאכות הפוגעות בצביון היום וסוברים שמדובר על איסור תורה.‏

The Rambam differentiates between two prohibitions:

1. Uvdin Dechol: A Rabbinic prohibition to do any activity that could be confused (or lead to) a Torah prohibition.

2. The Tanachic prohibition of VeDaber Davar - ruining the Rest days by doing non-restful activities. The Rambam apparently never refers to these as Uvdin Dechol. (Seems to me like the Ramban's definition of Uvdin Dechol.)

שיטת הרמב"ם היא שיש להבחין בין שני מושגים - איסור משום עובדין דחול נאמר רק כלפי פעולות הדומות לעשיית מלאכה בחול שיש חשש שיובילו בטעות לאיסור תורה. איסור עובדין דחול הוא איסור דרבנן ככל איסור השבות. בנוסף לכך הרמב"ם סובר שיש איסור דרבנן בפעולות הפוגעות בקדושת היום ודבר זה נלמד מדברי הנביאים 'ודבר דבר'. ‏

He concludes by noting that some Halachic authorities conflate the 2 definitions and refer to both of them as Uvdin Dechol. (Which is why it seems so difficult to define by looking at examples.)

יש המכנים גם סוג זה של איסורים 'עובדין דחול', והדבר שכיח בפסיקת ההלכה, אולם הרמב"ם הגדיר איסורים אלו בנפרד והקפיד על ההבחנה ביניהם.‏