Granted this is a very theoretical question but I thought I'd throw it in there and see what people think.

Do you think a small modern army (by small I mean 10-20 soliders) would be able to hold off a huge army armed only with ancient weapons?

Anything is up for discussion. How many Ancient soliders would be required pretty much as cannon fodder. Or how advanced an army would have to be before they could think of attacking a small well armed modern unit.

I'll leave it to you whilst assuming that most of you will think that a modern army could hold out indefinately against any number of ancient soliders provided the ammunition was stacked high enough!

:borg: :ar15: :ninja: :egypt:

:spear:

Aaah yes, the good old fashioned can-spearman-take-out-a-tank-because-that-is-just-what-happened-to-me-here!! thread..

Simple answer...it can go either way. Maybe not fifty-fifty chance, but the chances will depend on so many factors, any theoretical spamming will not get us to come anywhere close to a reasonable guess.

If the modern army had a machine gun, one guy could probably hold off 400.

If you want an interesting example of the application of drastically superior military technology then the Battle of Omdurman is a good example.

During an initial frontal attack the Ansar Army charged the British lines and lost 4000 men without any of them getting closer than 50 metres of the British lines. A combination of artillery and Maxim guns mowed them down in short order.

The final toll of the battle was 10,000 dead and 15,000 wounded on the Ansar side versus 48 dead and 382 wounded British.

You need to consider the conditions.

Is this on open terrain? Who is defending and who is attacking? Does one side have the advantage of fixed fortifications or surprise? Can the modern force use mobility or are they in a fixed position? What sort or ammo/supply situation does the modern force face?

10 to 20 soldiers is not very many and they have to sleep sometime. I think they would be over run in just about any position unless they were dug in on a mountaintop surrounded on all sides by steep slopes.

All you need is one guy and enough sarin... Guns are for the weak!

I reckon a 100,000-1 ratio at least, if the guy is adequately gas-protected.

Exactly - this sort of thing happened all the time in colonial days, which seemed to indicate that a very small force armed with serious modern weaponry could hold off - perhaps not an infinite number of guys with spears - but a hell of a lot of them.

Whatever happens
We have got
The Maxim Gun
And they have not!

Prior to the Maxim gun, there were a number of cases where the natives overran the more modern army. For instance, in wars against the Ashanti and the Zulu. The natives could also give themselves an edge by keeping the enemy awake and attacking when the enemy was exhausted.