[3R]对于 MM 的 Errata 中, Beholder and Gauth 的一点问题

[起个名字想半宿]

最近开始看MM,在MM后面的Errata中,看到这样一段:

Beholder and Gauth
Monster Manual, page 26

The eye ray attack is a free action. Increase its bite attacks by +5.

对于 "The eye ray attack is a free action. "这一句话表示无法理解.
翻回到Beholder那里,发现eye ray的可能相关的原文为:

Attack: Eye rays +9 ranged touch
Special Attacks: Eye rays
Eye Rays (Su): Each of a beholder’s ten eye rays resembles a spell cast by a 13th level caster.后略

难道这句话的意思是:
1.与PHB 154页中提到的冲撞,绊摔等等特殊攻击不同, 眼魔只需要消耗自由动作就可以使用eye rays这个特殊攻击能力?(自由动作应该是随意的谈不上消耗的吧,那么是不是有什么地方我理解错了)
2.并且eye ray这个能力的命中是远程接触攻击,加值为+9

另外,eye ray的使用是怎么判断的?由DM决定使用任意几个眼睛攻击?还是一次只允许有一个眼睛发挥作用?

有很多地方都不大懂 希望各位能不吝赐教

[mimir]

MM上beholder最开始有这段话：
Each of a beholder’s small eyes can produce a magical ray once per round as a free action. During a single round, a creature can aim only two eye rays (gauth) or three eye rays (beholder) at targets in any one 90-degree arc (up, forward, backward, left, right, or down). The remaining eyes must aim at targets in other arcs, or not at all.

[起个名字想半宿]

谢谢指点，看来是我自己看书不够仔细