Down here in the sunny south, beside the seaside, I run in leggings or shorts and a wicking base layer top. But in a few weeks time I'll be running / walking / crawling over some central Highland mountains, a mountain marathon, something I'm not used to.
I envisage wearing the same, but there are going to be cooler periods where other clothes will have to be added. Will a fleece, hat and Berghaus Paclite jacket and trousers suffice? I realise that weather changes and it's impossible to prepare for every eventuality, but I'd rather not become a casualty to the weather.
A humble newbie.

Running or "adventure racing"?

Hi Jeff, in the interest of keeping weight low, i'd say that'd be enough clothing. thin leggins though, not shorts would be my choice. Just make sure you pack a foil bag/blanket just in case though. A sprained ankle could see you slow down so much that even that much clothing wouldn't keep you warm.
good luck.

I only asked because there is usually mamdatory kit in organised events. I'd swap tights with a water-repellant treatment for the paclite pants and add gloves. If you're not going to be stopped/walking too much you can probably ditch the fleece too.

Partly depends on how far/high you're going and when, and whether you're likely to encounter snow.

Especially considering it did snow on the LAMM last year and quite a few folk got hypothermia...

The truth is.. all I know is it's the Central Highlands of Scotland and mid-June. www.lamm.co.uk gives you an idea of what's involved and a list of mandatory kit to take.

maybe a bit late now....but I've been training for a winter run, running about in a) an Icebreaker 260 weight zipped top b) the lidl/netto/ crane sports copy. the icebreaker was fantastic in the winter, snow caking on the outside, could be brushed off but not too cold, nor too hot. More wind-resistant than the looser-weave copy....but £60 instead of £10. The lidl top has been OK in the milder weather, but I'd still take a wind/water-proof.

the wool doesn't smell and feels OK when wet, not clammy!

will prob get a lighter weight icebreaker & try that.

Depends how hot you get when you run, how fast you'll end up going..... good luck & say hello to the midges!