A question about combat

[Knecht]

I share a continent with the Sioux and remained at peace with them until I was in the industrial age. By this time they had gotten so obstreperous that I was forced into a war with them. Frankly, I thought it would be a walkover because I was far in advance of them technolgically and had a lock on all the critical resources (iron & saltpeter). So now I'm fighting archers, spearmen, and warriors with riflemen and cannon and I'm barely holding my own. How can a spearman or an archer attack a rifleman in a fortress and win the battle? I'm only playing at warlord level, so I don't think the odds should be tilted much against me. What's the point of putting all your energy into science and high tech if it doesn't give you an advantage? I don't get it.
This is only my first game of Civ III and I was enjoying it until this little mystery arose. I must be doing something wrong but I sure don't know what it is. Any insights would be much appreciated.

[Altuar]

Its not your fault - there is something wierd in how the game randomizes combat. As the combat system stands, there is a chance that the spearmen will defeat your infantry with alarming regularity. This may be due to two things:

a- AI gets a bonus to combat rolls - unlikely, but the most logical argument.
b- There is a problem with the actual randomizer. One turn goes perfectly well while another turn sees my units get consistently slaughtered.

And one thing that is definite: since firepower is removed, it is not only possible but very likely that obsolete defenders (pikemen) will defeat your next-age attackers (cavalry), especially after defense bonuses, reduced as they are, factored in.