I noticed possibly nice abuse of the "invulnerability ghost mode" - when you respawn, you are a "ghost" for few seconds - you can't shoot, but nobody can shoot you. However if someone shares space occupied by you, you will remain ghost longer (as long as someone is at least partially blocking you from materializing. Apart from some annoying situations in deathmatch (especially on small maps these occur quite often) where you can be blocked from materializing and shooting anybody (or from other side, if you keep in same place as some opponent, you will not materialize and nobody can kill you), it could be abused in CTF - several players can "stack" their ghosts, so one tank and many ghost tanks go for capture. Only one can be killed and the rest of the tanks are invulnerable for the time being (only one tank from the stack being hitable at a time). This trick would be very useful on some maps where it is easy to defend, but hard to get the flag. The only problem would be coordination., though I think not an unsolvable problem :)

Hmm ... I looked through the Terms and conditions and there is nothing forbidding having multiple accounts ... so I think I'll create just a new account once I grow too high in rank to participate in low-tech battles :)

Well, degrading (if you would be allowed to keep your upgraded weapons) could bring some disbalance, but merely staying on one rank? There could be slight disbalance from novices playing with veterans, but if veteran would create another account and start playing from zero points, he'll still have novice tank, but veteran skills.... disbalance anyways. Currently, gaining in rank does not bring only advantages (ability to buy better weapons and participate in more advanced battles in more advanced maps) but also disadvantages (inability to participate in good old low-tech battles), so that is why I want this .... Another solution could be to add limit on weapons (and also paint/chassis) level when creating battles - you will create battles accesible to all ranks, but limit weapons to say, Sergeant level. Anybody wishing to participate in the battle must use weapon, with first level available at the weapon limit of the rank and if they have weapon upgaded more than the rank allows, the weapon will be temporarily downgraded to permitted level during battle. This way veterans can fight with relative newbies (which already happens now, as many battles allow wide range of ranks), but the battles will be more fair (skilled veterans would have to win through they skill, not because they have weapons that are magnitude better than what others have) and thus more balanced. Then there would be no incentive for people to stop progressing with ranks, as you could then technically temporarily downgrade the rank with all the effects (available weapons, etc ...) for one battle you wish to join.

That command would add score? But I want the opposite - to decrease my score, so I'll stay within my current rank ....

Is there any way to either prevent gaining higher ranks (other than not playing) or somehow degrade yourself rank down after you gained a rank? Or perhaps somehow spend the points used to determine the rank on anything? I'd like to stay Sergeant for some time, so I'll be still allowed in all those low-tech only battles (i.e. those without railguns or other advanced weaponry).