Actually, $chan, $nick, and other event identifiers are maintained and available from aliases that are called from within that event.
on *:TEXT:*:#:{
myalias $1-
}
alias myalias {
echo -s In $chan $+ , $nick said: $1-
}
@OP, it looks like your /dice alias requires parameters. Probably the value of the dice you want to roll. If there are no parameters, nothing will happen.
-genius_at_work