Robo Rally is a fun game but the option cards totally break it if a person just sits on the wrench and hammer and collects them all.
Has anyone tried a house rule to discourage this behaviour? How did it work out?
This uses the online PDF from http://www.wizards.com/avalonhill/rules/roborally.pdf
You aren't allowed to "sit" anywhere.
You have to play cards. If you time-out, the player to the right plays random cards to fill out your non-locked registers. (p. 4) Locked registers WILL be played.
All movement Cards used but not locked are discarded, as are unused. (p. 4, 8) New ones will be drawn.
You only get one draw of an option card per turn, and only if you END the turn (and thus also Register 5's phase) on it. Crossing it during the turn doesn't get you the card. (p. 8)
The odds are not good in 3p or more that you'll get the cards needed to return to your start space.
Camping on a repair spot is thus not as easy as it may seem. Especially since you retain only locked cards. If one gets consistently lucky enough to have the ability to return to start spot with cards alone, it's great. If one is using terrain, it's skill, more than luck.
In short, I suspect the problem isn't the option cards, but a misread of the rules.
If there was no misread, one simple solution is to use a 1 per space limit; put a (custom) player token on each upgrade spot, and when you draw an option card, put that token on it. When it's lost, put the token on an upgrade slot where you don't have one.
I've never felt it needed, and the people I've known who did usually were making one of three mistakes:
1) retaining unused programming cards, thus being able to plan multiple turns ahead
2) retaining used programming cards. This makes it a VERY different game.
3) allowing repairs and upgrades each register phase, rather than only at the end of the turn. This makes camping on a spot far more worthwhile.
The best way to discourage this behavior is to remember it's a race, and start racing.
Grabbing early options is actually a very good strategy -- it maximizes the use you'll get out of them during the game. But once you've got a few loaded up, get your butt moving. Every turn your opponents spend option camping is a turn you get to advance without them messing with you. Unless the cards royally screw you (you don't get any move cards for a few turns, or somebody lucks into a devastating option combo), the head start they're spotting you can be very tough to beat.
It's a lot easier to camp a "Toy Spot" than some of the other answers are making out. To combat this, we institute a limit of 3 options. If you would get a 4th you must choose and discard one of your options BEFORE you draw a new one. This reduces the camping to a good extent, but doesn't stop it either. And of course, if someone is camping constantly, coming over and shoving them into a pit, or shooting the crap out of them can be the simplest method to solve the problem. Or just go tag all the flags and win while they're collecting toys.
It's not in the current set of rules, but to avoid option hoarding my play group always said that you only get a new option card if you go to a different repair bay slot (you can use your archive token as an indicator of this). So, you can go back and forth between two double wrenches to collect them.
I agree that it's all too easy to rotate and get several option cards - usually other players are not close enough to 'just blast them either'. So I've decided on a simple house rule that says you must move off the hammer-wrench before you can go back on to get another card - i don't mind so much if someone can go 'back 1' and 'forward 1' again, as these card combo's are much less frequent than rotate left & right. It works well, simple and effective.
While option cards can be handy, most of them aren't going to buy you a full turn, so I'd recommend the simple strategy of:
I don't really see a problem with too many option cards. With solid planning I usually need about 2-3 complete Turns to get to the next Flag, if the other players aren't actively blocking me. So if we both start, you take 2 turns to your Repair-Shop I'm already at the first flag. If you stay there for 5 more turns (and manage to just collect your option cards, without people shooting at you and without a stroke of bad cards or someone pushing you) - fine you than have 5 RANDOM option cards. I will at this time probably be at Flag 3 - where as you have to go to Flag 1.
Sure if you are lucky, maybe you get the right cards to get amazingly fast or to kill everyone else. But on small maps the racer will already be at Flag 3 of 4 or 5 and will win the game before you can get him. On a Big map he is probably too far away for you to actually get him properly with your option cards. And if you get too strong, all it takes is 3 Players ganging up on you and shooting you and your cards to hell...