The best possible defense value for a unit in a city

[wieder]

Basic example with a v warrior:

warrior (1) * veteran (1.5) * base city defense (1.5) * city size 9 (1.5) * city size 20 (1.5) * on mountain (2) * with river (1.25) * city walls (2) * underground tunnels small wonder (2) = 50,625.

It's now possible to build really well defended capitals sine you can build on a mountain and also get extra defense for one city with the underground tunnels.

[Caedo]

Now hold on. I'm not sure how you implemented this in the ruleset, but there's no way all of those are multiplicative. For one thing, all defense bonus effects (presumably those from city size, city walls and tunnels) add, so they're +50% +50% +100% +100% for a total of +300%, so *4, instead of *9. I'm also not sure if the mountain and river bonuses are multiplicative – they should be, but I wouldn't bet on it.
So all of this would be at least brought down to ~23 defense, maybe further.

[Corbeau]

I thought all bonuses in Freeciv are multiplicative. The ones in original Civ weren't.

[Caedo]

All the different bonuses in Freeciv's supplied rulesets are multiplicative, since it's never possible to have multiple Defense_Bonus effects applying at the same time. However, as with any effect type, the values of all active effects are simply added, so if there's one Defense_Bonus effect with a value of 50 for a city of size 9 and another with a value of 100 for city walls, they're the same effect type and thus added up, giving a total value of 150, or +150% (or *2.5).

Now, I haven't looked at LT40's effects, it's quite possible wieder planned for this and added additional effects that would make this act like it's multiplicative (e.g. an additional +50 for a city of size 9 with walls, to bring the total up to +200% and thus *3).

EDIT: The effect type is Defend_Bonus, not Defense_Bonus.

EDIT 2: Also, there seems to be an additional +50% Defend_Bonus in a city, apart from the built-in factor of 1.5. However, this defense only works against land units. The city size bonuses also apparently don't work against air units. There's also the Great Wall, which gives another +50%. All in all, one can get a +400% (or *5) Defend_Bonus against land units. Multiplying this with the base city defense factor, mountains and river, we get a maximum factor of *18.75. For a veteran warrior, this comes to 28.125 defense. For a maxed-out warrior, it's 65.625. For a maxed-out battleship, it's 1312.5 (assuming the Great Wall doesn't get obsolete).

[wieder]

It remains to be seen how many errors there are and how the changes will actually work. There are lots of changes... Lots of stuff...

Lots of tests but also many things probably unnoticed.