The principle of requiring Intentional Work for full violation of Shabbat is like a Mountain dangling by a Hair: Chagigah 10a, 10b
General Rules of Transgression without Intention - She'Eino Mitkavein
Source for treating such transgressions differently by General Prohibitions: Pesachim 33a
Where the Prohibited act is guaranteed to happen: Shabbat 103a, 111b, 133a, 143a; Menachot 41b
Violation of a prohibition which warrants Divine ex-communication, while attempting to fulfill a Mitzvah: Succah 41b, 42a
Liability for a Transgression Committed while Doing A Different Act - Mis'asek
By General Prohibitions: Shabbat 72b-73a; Pesachim 33a
By Shabbat: Shabbat 72b-73a, 75a, 92b, 107a
Where the Prohibited act is guaranteed to happen: Shabbat 75a
Above, where he is adversely affected by the prohibited side-effect: Shabbat 75a
By Illegal use of Holy Offerings: Pesachim 33a
Killing a dangerous snake/scorpion by stepping on it in one's ordinary path of walking: Shabbat 121b
By Measuring on Shabbat: Shabbat 157b
Rules of Violation by Inevitable By-Products of Actions
Establishing a case to be one of an Inevitable Byproduct, against the Majority of Cases: Ketuvot 6b (See Rashi)
Where the action was unintentional, but the result of it was inevitable: Shabbat 75a, 103a, 111b, 117a, 120b, 133a, 143b; Succah 33b
