[The Blue Knight (so ha!)]

my brother has an eldar ulthwe force, stocked full of vehicles and hardhitting close combat units. what should one do to defeat this kind of an army with Space Marines?

[Cpl. Smith]

Using some Terminators would be a good start, especially equipped with an Assault Cannon. Possibly some Assault Squads and a Land Speeder equipped with a Multi Melta. Are you using a specific chapter or a vanilla army?

[The Blue Knight (so ha!)]

im using space marines with allied grey knights, so i could use my terminators and grey knights to deepstrike (normally works well). its just killing his vehicles that is tough. Even with melta bombs because he uses holoshields, so the most any of the bombs can do is a penetrating hit.

[ShadowCrawler]

He is talking about me, holo fields do count against grenade lobbing in cc right? Also I play Iyanden.

[citizen_kodo]

Yup, Holos work against any damage source. Also, Melta-bombs, being considered as a melee attack, only hits Skimmers on 6s .

Your best bet VS Eldar skimmers (Wave Serpents and Falcons I presume?) would be 6-men Devastator squads with 3 Missile Launchers___then you'd have enough range and firepower to reliably Glance your bro's skimmers every turn (remember, they have to move at least 6" to be glanced, as well as finishing their move at more than 6" from where they were positioned at the start of his turn). Also, since your bro's playing Iyanden, MLs will be inestimable to whack his mandatory Wraithguards an' Wraithlords.

[ShadowCrawler]

sweeeet, very nice to know