Concetrate to cast a spell?

[jason schultz 848]

To cast a spell, you must concentrate. If something interrupts your concentration while you're casting, you must make a concentration check or lose the spell. When you make a concentration check, you roll d20 and add your caster level and the ability score modifier

So has i take it, to just cast a spell i will need to concentrate unless im in an area where i could take 10 or 20. That is what the rule sounds
like. So is this right or an errata. my players say you only need to make
the concentrate check when your interfeard with.

thanks for your help

[VRMH]

You make a new Concentration check for every distraction. If you take damage from multiple sources, you make multiple Concentration checks. If you're being shaken about too, you have to make a separate check for that. Fail any one of them, and you lose the spell.

[jason schultz 848]

VRMH wrote:

You make a new Concentration check for every distraction. If you take damage from multiple sources, you make multiple Concentration checks. If you're being shaken about too, you have to make a separate check for that. Fail any one of them, and you lose the spell.

thanks for clearing that up for me VRMH