Try typing "fortune" at the bash prompt - if you get a response then it is installed. If not you will need to install the fortune package.
To show a fortune on login slackware uses a script:
/etc/profile.d/bsd-games-login-fortune.sh
Containing:
Code:
#!/bin/sh
# Print a fortune cookie for interactive shells:
if [[ $- = *i* ]]; then
echo
fortune fortunes fortunes2 linuxcookie
echo
fi