2 years ago or so I GM:ed MC, and while some things with 2D20 are cool, some other things are not. One of these things were combat. It is sloooooooow to say the least. We ended up changing it so that we did not have any bodyparts to care about at all, but it is still clunky especially with the whole momentum mechanic.
Has anybody thought of a simplified combat system? I do have some ideas, but wanted to check first.
Have you tried the Mutant Chronicles adaptation for Savage Worlds?
This is an official variant edition of the core book, so it should be easy to adapt.
What exactly was so slow in your experience.
The Momentum mechanics are at the very core of the 2d20 system - every 2d20 variant for all the other 2d20 based RPGs uses them. So it is an integral part that is not easily to be replaced or even dropped.
In my experience, some practice for players and GM helps a lot. The Momentum spends, even the individual costs are soon known by everyone and used without delay.
And even before they’re memorised, it should be possible to put together a cue-card list as an aide-memoire. There’s possibly one already out there on t’interweb somewhere.
While MC3 is the earliest iteration of the 2d20 system, and thus more involved than e.g. STA, Momentum is still a key mechanic throughout 2d20. If you wish to do without that, but keep the MC setting, the Savage Worlds version could well be an easier solution than rewriting 2d20 without Momentum.