Dear SSL community,

*Rule change* I would like to bring your attention to a change in the SSL rulebook https://robocup-ssl.github.io/ssl-rules/sslrules.html. A new substitution area has been created behind the goals on Div A fields. This is done by extending the width of the area behind the goals from 0.3 meters to 0.6 meters. The new rule can be found in section 9.1.1 Goal Substitution Area (Division A only) https://robocup-ssl.github.io/ssl-rules/sslrules.html#goal-substitution-area

*A robot is considered to be in the Goal Substitution Area if it is at least 0.3 meters outside the field, behind its own goal line. Robots are allowed to remain in the Goal Substitution Area while the game is running. They are allowed to move freely and must comply with the following rules:*

- *Minimum ball distance during stop or free kick* - *Must not interfere with ball placement*

Additionally, the following line has been added to section 3.1 Number Of Robots https://robocup-ssl.github.io/ssl-rules/sslrules.html#_number_of_robots

*Robots in the Goal Substitution Area do not count towards this limit.*

*Protobuf message* Following the rule change, the protobuf message messages_robocup_ssl_geometry.proto has been updated with two new fields: *boundary_width_goal_line* and *goal_substitution_area_width. *

*Autorefs, GC* The GameController and the TIGERs autoref have been updated in accordance to this rule change.

All latest changes to this year's rulebook can always be found at https://robocup-ssl.github.io/ssl-rules/sslrules-diff.html

Best regards,

Emiel Steerneman - TC