Accidents

[searcheagle]

Well things happen.

I think that for any unit there should be a chance that the unit gets destroyed or damaged from their own actions, weather, etc.

Land units get destroyed in all sorts of ways. Traffic accidents anyone?
Ships still sink (Even after triremes)
Airplanes still crash

The chance for these things should be very small, but with the number of units and turns this will have an impact. And the chance will go down as you gain expecience with the units (like the way its supposed to work with sea units in Civ3-I can't say if it does or not)

 

[ybbor]

but if you build a bomber, it doesn't represent 1 bomber itrepresents a division, now the odds of 1 or two of those crashing is preety low, but the odds of the entire battalion crashing (unless thier under fire) are astronomical

 

[socralynnek]

and things like this and "friendly fire" is represented by the small chance of older units to defeat the newer ones...

 

[Pook]

Remember that you're paying 1 gold per turn for maintenance. This can pay for replacement weapons/ships/aircraft that you lose from accidents & normal wear & tear.
The potential loss of a trireme/caravel is to cover the idea that prior to navigation, there was a possibility of losing an entire fleet of ships. As despair.com points out, "Until you have the courage to lose sight of the shore, you will not know the terror of being forever lost at sea."