Recently I've been thinking of some experimental things to add for unorthodox combat situations. To often I find that my players try to play the elimination game against opponents that I have added with the intention to rush players along/add tension and excitement to otherwise dull check rolls. Sure this is a fun and great method for the final battle, but when the point of an encounter is to hack into the mainframe to get data because the players know going against the full might of (insert villain's name here) is suicidal, I find that I am either forced to leave a few players hanging as the scene plays out for the slicer/stealth guy, or get tugged into a combat situation where the fighters methodically eliminate every minion before the other players try to move on to their task. There are a couple solutions I have thought up to add a surprise that jostles the players out of their tactical habits narrativly.
The first one is Rival groups. The point of these is simply to scare the PC's without putting the part at risk of a TPW. What i did last week was Introduce a large number of weak rivals, and run them as minions with a few key changes. The first was to not insta-kill on crits. the second my marauder's vibro-great sword DIDN'T cleave the head off his enemy instantly, he panicked, and started to think out of the box. Now, the PCs could have fairly easily dealt with the group presented before them. But this small change got them back into the story, and gave them a reason to think that they don't quite have have me figured out.
I talk abut this with one necessary understanding. This is something that should only be done rarely. It should be used sparingly because if the players ever decide to lay into the rivals, they will 1). learn they can still beat them bloody in combat, and 2) the combat will take longer ( the lack of inst kills) and the Critical hit becomes devalued.
Even understanding this I welcome feedback and criticism. as well as other ideas for this kind of unorthodox combat situation.