A lot of the challenge (in term of difficulty i mean) from 34.11 has been lost since df2014 , the game became easier in similar conditions .
I find it that trap is something to be avoided if you're looking for challenge against the goblins, because unlike 34.11 , the gobs will never bring any weaponmasters in their ranks (i wonder if the lack of them is a bug or if it's a huge overlook), so your legendary have actually no match, while in 34.11 if the gobs had enough weaponmasters , an open battle could very well decimate your troops even if you had a few legendary in the middle.
You had to be tricky to even the odds, but since df2014 there's no more need for tricks and traps against gob sieges, with time (and so with more legendary), the further gobs sieges will be decimated by your troops.
Only the undead siege is requiring tricks, because unlike in the past (i mean 34.11 and earlier) in which the big strength of the undead sieges were in the numbers + the re-animations of fallen troops, df2014 and 42.x undead are now insanely strong and will punch through the best armors without much problems.
So if you embark near a tower, you will need good defenses and traps, especially as undead siege do not care about the population 80 trigger like the goblins.
Now if you're uninterested by fighting broken undead, and still prefer the goblins and their mounts, be willing to edit files to have earlier goblins sieges or change the conditions to make the game more fun, you can open the file
entity_default.txt
in the raws/objects/ folder
In the [ENTITY:MOUNTAIN] (that define the dwarves entities), look for
[PROGRESS_TRIGGER_POP_SIEGE:3]
[PROGRESS_TRIGGER_PROD_SIEGE:0]
[PROGRESS_TRIGGER_TRADE_SIEGE:0]
This is what controls the goblin siege
By default , it means that goblin are willing to siege you at +/- 80 population ( PROGRESS_TRIGGER_POP_SIEGE:3 )
But your production and trading wealth has no bearing on their willingness to siege ( PROGRESS_TRIGGER_PROD_SIEGE:0 and PROGRESS_TRIGGER_TRADE_SIEGE:0 basically means both triggers are disabled)
For the values, the pop_siege trigger :
A value of 0 disables the trigger. 1 corresponds to 20 dwarves, 2 to 50 dwarves, 3 to 80, 4 to 110, and 5 to 140.
the prod siege trigger
A value of 0 disables the trigger. 1 corresponds to 5000☼ created wealth, 2 to 25000☼, 3 to 100000☼, 4 to 200000☼, and 5 to 300000☼.
the trade siege trigger
A value of 0 disables the trigger. 1 corresponds to 500☼ exported wealth, 2 to 2500☼, 3 to 10000☼, 4 to 20000☼, and 5 to 30000☼.
So according to this, to increase the challenge against gob siege, you may want to change
[PROGRESS_TRIGGER_POP_SIEGE:3]
[PROGRESS_TRIGGER_PROD_SIEGE:0]
[PROGRESS_TRIGGER_TRADE_SIEGE:0]
[PROGRESS_TRIGGER_POP_SIEGE:1]
[PROGRESS_TRIGGER_PROD_SIEGE:1]
[PROGRESS_TRIGGER_TRADE_SIEGE:1]
So gobs may be willing to siege when
- you reach 20 pop
- or you reach 5000¤ of created wealth
- or you reach 500¤ of exported wealth
Meaning that instead of +/- waiting 3 years to reach pop 80 for a goblin siege to really come (and so be very prepared with strong enough by the time military to destroy them all), you may be able to be sieged by the 1st year.
Now something else i noticed when looking at the entity_default.txt is that the goblin entities ( [ENTITY:EVIL] ) is lacking the
[AMBUSHER]
tag (only the kobold, elves and subterrean people entities have it)
This may explain why i never saw goblin ambushes since df2014 while they were doing that in 34.11
So adding [AMBUSHER] to the [ENTITY:EVIL] could be helpful to have early challenges.
NOTE : changing the raws may require to generate a new world for them to take correctly effect