Great game

[DRG]

Their suppression level is important. If they are pinned and highly suppressed and you can get your troops one hex away you get to-hit bonus that almost always pays big dividends

I know its tiresome to be told to RTFM and I know it's long and involved but there is good info on game play there.......

If you need to advance infantry under enemy fire, to close or to retire or whatever, then you should first use (hopefully) stationary squads (or better yet AFV in close support) to fire covering fire at all known enemy infantry and MG, in the hopes you will shut these down, before you move the squad. Even if you do not pin the enemy or worse, the added suppression all makes it more difficult for him to hit the squad(s) you later intend to move. Use the Z key to fire suppressive fires into hexes you suspect have unlocated enemy infantry in them, if you have shots to spare (it is not very effective). If you have MMG or HMG, then when advancing, wait till these are set up and ready, and try to keep them outside rifle range whilst using them to hose down any located enemy (or leave with some unexpended shots for opportunity fires on enemy firing in their turn

Open the game guide and press CTRL+F and search for suppression.... there are 40 entries and they all provide info