Guild Wars 2

This would be an alternative siege ability in WvW.

a. Basic ladder construction (quick to build but also quick to destroy); allows players to scale one level of wall.

“Stairs” could be used to overcome the game mechanics of vertical climbing to simulate such siege equipment (if the game mechanics do not allow for actual “ladders”). “Stairs” could be both unshielded and shielded depending on the type deployed.

And these are non-mobile. Once in place, they cannot be moved.

Not a chance as long as a mesmer can port 20 people in instantly.

great idea – BUT Anets first query will be – should a small grp of ladder wielding players be able to take over a tower and bypass the gate? negating all other siege equipment….
Will large grps use ladders instead? – the NPC archers on the walls couldn’t hope to destroy all the ladders quickly enough. Then mesmer pops the remaining players from the outside in . – this is a major problem…
The first problem with any idea like this is —> mesmer portal. Perhaps using a ladder puts portal on 3 min cooldown?
IDK, but I like your ideas.