Official Challenges

Act One (Challenges 31-40) Post anything related to Act One challenges 31 through 40. Alternate solutions, questions, hints, or error reports are all welcome! Act One (Challenges 41-50) Post anything related to Act One challenges 41 through 50. Alternate solutions, questions, hints, or error reports are all welcome! Act Two (Challenges 81-90) Post anything related to Act Two challenges 81 through 90. Alternate solutions, questions, hints, or error reports are all welcome! Act Two (Challenges 68-70) Post anything related to Act Two challenges 68 through 70. Alternate solutions, questions, hints, or error reports are all welcome! Power Pack (Challenges P1-P11) Post anything related to Power Pack challenges P1 through P11. Alternate solutions, questions, hints, or error reports are all welcome! Act One (Challenges 61-67) Post anything related to Act One challenges 61 through 67. Alternate solutions, questions, hints, or error reports are all welcome! Act One (Challenges 51-60) Post anything related to Act One challenges 51 through 60. Alternate solutions, questions, hints, or error reports are all welcome! Act One (Challenges 11-20) Post anything related to Act One challenges 11 through 20. Alternate solutions, questions, hints, or error reports are all welcome! Act Two (Challenges 141-149) Post anything related to Act Two challenges 141 through 149. Alternate solutions, questions, hints, or error reports are all welcome! Act One (Challenges 1-10) Post anything related to Act One challenges 1 through 10. Alternate solutions, questions, hints, or error reports are all welcome! Act One (Challenges 21-30) Post anything related to Act One challenges 21 through 30. Alternate solutions, questions, hints, or error reports are all welcome! Act Two (Challenges 91-100) Post anything related to Act Two challenges 91 through 100. Alternate solutions, questions, hints, or error reports are all welcome! Act Two (Challenges 101-110) Post anything related to Act Two challenges 101 through 110. Alternate solutions, questions, hints, or error reports are all welcome! Act Two (Challenges 71-80) Post anything related to Act Two challenges 71 through 80. Alternate solutions, questions, hints, or error reports are all welcome! Act Two (Challenges 131-140) Post anything related to Act Two challenges 131 through 140. Alternate solutions, questions, hints, or error reports are all welcome! Act Two (Challenges 121-130) Post anything related to Act Two challenges 121 through 130. Alternate solutions, questions, hints, or error reports are all welcome! Act Two (Challenges 111-120) Post anything related to Act Two challenges 111 through 120. Alternate solutions, questions, hints, or error reports are all welcome!

Topic	Replies	Views	Activity
About the Official Challenges category Official Challenges	0	1046	January 9, 2022
How can Act One challenge 29 be built with two junctions as Natalia mentions? Official Challenges	2	33	May 25, 2026
Challenge 147 chains Act Two (Challenges 141-149)	0	175	January 21, 2026
Mistake in Challenge 84 Act Two (Challenges 81-90)	2	1305	January 18, 2026
Difference between 6and 7 Act One (Challenges 1-10)	1	873	October 9, 2025
Challenge 67 Solution Improvement Act One (Challenges 61-67)	1	1328	May 1, 2025
Challenge P2 Circuit Incorrect Power Pack (Challenges P1-P11)	1	1250	March 22, 2025
Help with challenge 95? Act Two (Challenges 68-70)	0	590	March 22, 2025
Challenge 31, what should be the output? Act One (Challenges 31-40)	2	1287	March 21, 2025
Challenge 23 - can't get it to work as described Act One (Challenges 21-30)	1	840	December 31, 2024
Add a tip to Challenge 31 Act One (Challenges 31-40)	3	2020	April 13, 2024
PP11 -Alternative Circuit Diagram Power Pack (Challenges P1-P11)	0	1548	February 16, 2024
PP10 Alternative Circuit Diagram Power Pack (Challenges P1-P11)	0	1021	February 9, 2024
Challenge P7 - around the outside Power Pack (Challenges P1-P11)	0	1040	January 19, 2024
P6 alternate solution Power Pack (Challenges P1-P11)	0	1108	January 18, 2024
Challenge 148 - effect of gear ratios Act Two (Challenges 141-149)	0	1121	January 17, 2024
Challenge 144 IRL Act Two (Challenges 141-149)	2	1534	January 9, 2024
Challenge 134 - issues with Start Act Two (Challenges 131-140)	0	1133	January 2, 2024
Challenge 132 issues Act Two (Challenges 131-140)	2	1537	January 2, 2024
Challenge 137 remember to keep the chains loose Official Challenges	0	1033	November 26, 2023
Part 1 Challenge 13 & Challenge 15 Act One (Challenges 11-20)	1	1492	July 17, 2023
Typo in Challenge P4, Hint #1 Power Pack (Challenges P1-P11)	0	1100	April 2, 2023
Challenge 147 Switches Act Two (Challenges 141-149)	2	1494	March 31, 2023
Challenge 142 Solution Schematic is Incorrect Act Two (Challenges 141-149)	1	1327	March 31, 2023
Challenge 145: Typo in Hint 3 Act Two (Challenges 141-149)	1	1202	March 31, 2023
Incorrect Parts Listing for Challenge 130 Act Two (Challenges 121-130)	1	1137	March 31, 2023
Incorrect Hint for Challenge 126 Act Two (Challenges 121-130)	3	1453	March 14, 2023
Incorrect Hint and Solution Text for Challenge #127 Act Two (Challenges 121-130)	1	1142	March 13, 2023
Help with challenge 22 Official Challenges	1	1637	February 26, 2023
Challenge 64: Alternative solution for a voltage tripler? Act One (Challenges 61-67)	2	1698	February 25, 2023