Originally Posted by Simon Appleton
The best thing with elephants is to target them with missiles - all archers should aim for them. You may not kill many, but they have low morale and will panic.
Also, you should entice the elephants to charge your peltasts. Set the peltasts on loose formation and the elephants should not be able to kill many initially. Moreover the peltasts skirmish so quickly, the elephants probably won't catch them until they are nearly at the map edge. This buys you enough time to kill the rest of the AI army and allow you to focus on the ellies when they return from killing the peltasts.
If you can make the elephants run away, they are much more vulnerable to being killed while being pursued. Light cavalry can do it and it is vital to keep pursuing them to stop them rallying. But don't send your general to pursue or fight elephants - they hit so hard, your general may well die.
If you have to, phalanxes are not too bad against elephants - just as they are good against cav. But relying on the above tactics is more efficient.
Good hunting!