Supplies in Steel Legions:
Ammo: Aside from your basic ammo, everything else needs replenishing. That means you either need to find or buy nitro and neon ammo. This can be done for gold coins or by destroying marauders who drop it (rather infrequently if you ask me)
Oil: Everything works better when you’ve got oil so you need to try and keep all the parts supplied with it. More can be got the same way as ammo: purchase or pick up.
Repair kits: They are exactly what they sound like, quick ways to get repaired and back in the action.
Medic Packs: These are for your crew members. This is vital since you invest in them to train them up etc. You don’t want to lose them.
You can buy more of the supplies for gold or gather from drops by Marauders. This is one of the unbalanced areas of the game for those who spend real world cash vs. those who don’t. Oil for example, when you have enough and have the levels filled offers 20% extra damage for weapons, 20% extra speed, 20% efficiency for tactical weapons and 20% extra defense for armor.
The problem in Steel Legions is that oil drops so infrequently from Maruaders that you are almost always without it. That could effectively mean a 20% power difference between players who spend cash and those who don’t. This is, of course, their plan, they need to make some money off the game and the only way to do that with a free-to-play game is to push players to spend real money (or advertising which I talk about later).
Gold vs. Grinding
You could choose not to spend money and grind-grind-grind, but it could be hours before you see a good amount of oil drop from the Marauders. Eventually, you might run out of oil, repair kits, medic packs and even special ammo. Then you’d be at a very distinct disadvantage, possibly to the point where the game is no longer fun for you. Casual players will probably end up in this category. More hardcore players will log in every day to get the small daily bonus, spend cash to be better than everyone else and pretty much annihilate anyone who doesn’t do the same.
To me that will probably be the major problem with the game. Balancing it for those who don’t spend money vs. those who do. Do they really need to care about you if you’re playing and not spending money? Well, if they want to make a fair and balanced game they should. They have incorporated SponsorPay which lets you purchase gold, $7.50 for 1000 coins and they also offer prime deals where you sign up or test out some service and can get some free gold out of it.

Some of those offers require you to buy something from the partner before you get your gold. Again, spending money to get them. Many of the offers require a credit card which could cut out a large section of gamers.The same with Sponsorpay. You will need either a credit card, mobile phone (it will be added to your bill which is common in Europe) or you can use an ultimate game card, Western Union, Paypal, bank transer (if you’re willing to wait for up to a week) or a Visa electron card. You could also send them cash through the mail as a last resort, but who would actually do that?