How to keep score fairly in group games
Write the scoring rule before play, show the totals, and apply corrections to every affected team.
Updated
Record the rule
Specify the points for a correct answer, passing and any penalty. Do not introduce a surprise bonus after seeing who benefits.
Record every round
Record scores round by round instead of replacing a total without a note. Let teams check the addition at a break.
Handle disputed answers
Pause scoring for that question. Check the source and the exact wording, then announce a decision that applies to all teams.
Separate speed from knowledge
Use a fixed response window when the aim is knowledge. If speed matters, say so beforehand and use the same start and stop signals.
Correct openly
Name the corrected round and new total. A calculation error should not stay because the score was already announced.