in protoss vs terran matches, I just can't counter the marauder rush. Their concussive shell makes zealots useless and they will rip off my stalkers. Any ways to counter the marauder rush?
get senties to block your ramp with FF until you have time to build up your army a bit. also, if you can use enough FF to trap the marauders from kiting your zealots, you can kill them quite quickly.
Zealot/sentry and zealot/stalker can do well enough against rauder pushes. You need just enough zealots to tank the damage and deal damage with stalkers or sentries. Sentries have the same survivability as stalkers vs marauders, and while they deal less damage they cost less minerals allowing for more zealots to tank hits. Also you need to micro a bit, pull off the wounded zealots to regen their shields and put them back in to tank another 5 extra shots, since that's like 100 stalker damage you could have avoided. If he aims for your stalkers first, pull them back asap and let the zealots hack the rauders, till they resume their kiting where you'll bring your stalkers back... It takes a good deal of micro for protoss to deal with early mm pushes, but it's not hard... Also some care about your composition: too many zealots will get you kited to death, too many stalkers will have no zealot meathields to take the damage and die, so you need a good balance there. Also hiding some zealots and flanking the enemy mm ball will positively surprise you with the results...