CapnZapp
Legend
The OotA adventure uses the demon summoning variant that way and it bugs me greatly.If she's getting her ass beat, boom she hates in a few vrocks
Why? Because all summoned monsters disappear when their summoner dies!
The only strategy that gives summoned monsters any chance at all of impacting the encounter is for the marilith to summon them as soon as possible, preferably before the fight even starts! (The second before it starts, that is. They only last one minute)
Any DM directive of "Ilvira summons a Yochlol when bloodied" is nonsense.
The most likely outcome of that strategy is that the yochlol appears and disappears without even taking an action (if you roll initiative; otherwise it will get to make one (1) action).
The best way to use summoned monsters is to send them into the fight without you even being seen. And only revealing yourself once the party have committed to fighting the summons (bloodied or killed at least one of them), presenting the party with the difficult choice of
a) continuing to kill off the summonings - otherwise all resources (actions, spells, etc) used to hurt the summonings will go to waste
b) switching to kill off the summoner and main monster - allowing the battered but still functional summonings to keep attacking the party for a maximum length of time (namely when the summoner is completely fresh and ideally buffed up too)
The ideal is to hold off until it would take slightly less effort by the party to kill off the summonings through direct means (i.e. attacking them) than through the indirect means of killing the summoner. Assuming the bunch of summonings as a group presents a comparable threat to the summoner, that is.
Meaning the party is encouraged to hold off attacking the main monster for ever so shortly...
![Devious :] :]](http://www.enworld.org/forum/images/smilies/devious.png)