Rules for a casual pick-up robotics game

[kenfox]

Our team has been working on an idea for a casual pick-up FRC game with a couple other Michigan teams. There are more complete rules in https://github.com/FRC3322/pick-up-robotics, but I've pasted the intro here.

Anybody try something like this before? Anyone see obvious holes?

We haven't started play testing yet. I figured I'd ask here since there are a lot of people very good at taking apart games.

The idea of a pick-up robotics game took shape on the bus ride back from St. Louis. A bunch of us were excited about completely student-built OCCRA style robots, but we also wanted a game that could be played without any complicated field setup or scheduling or referees.

The rules are still evolving, but this is how it works:

• A few students build a small FRC robot: 2 foot square and 60 pound max.
• OCCRA build restrictions are followed. Students and non-precision tools only!
• They post a meetup to other area teams to play a game.
• One group brings the field--it's small enough to fit in the trunk of a car.
• Students inspect each other's robots and lay out the field.
• Matches are played using standard driver stations in practice mode.
• When the batteries are dead, everyone goes home.

[GeeTwo]

The game I came up with won't quite fit in a trunk, but it can be packed on a small SUV's roof (I have a Saturn Vue), or even inside. A simple, inexpensive field build was definitely intended. I'm not familiar with OCCRA, so I don't know how that fits. The game rules are on this thread. The game was designed to reward autonomous programming, with "partial credit" for programming sensors.

[evanperryg]

1625 puts on a similar event yearly for local teams. Teams use VEX cortexes/signal splitters to control small (about 18x18x18) robots. I'm sure one of them would be willing to offer advice.

[Jacob Bendicksen]

1540 runs BunnyBots, which is somewhat similar to what you're describing, but with FRC-class (120 lb) robots. Rules will be out September 1st, but if you're curious, there's tons of info available here.

[kenfox]

Bunny Bots and Ball Bot both look really good! They remind me more of the OCCRA (Oakland County Competitive Robotics Association) games than what we've done. Your games are much more like FRC than the game we have.

The pick-up rules we have are designed to be played every year without any changes. The matches are competitive, so alliances have to play each other, not just play to the rules. We also have flexible robot numbers and unlimited human players so everyone can stay busy. The wide open field sort of required lots of human players to catch loose balls.

[kenfox]

I haven't gotten any feedback on the rules themselves. Maybe they are too buried in that github project. Here's the latest version of the rules in an easier to read format.

It's a reverse capture the flag game that is very competitive. We intend a box on wheels with a solid drivetrain to be useful with good driving. The meta-objective is to develop skills that directly translate into FRC builds and driving.

Objective

Be the first alliance to put all its balls into the goal. There are no points scored, only a winner. If time runs out, the winner is the alliance with fewest balls remaining.

Alliances

A match is played between 2, 3 or 4 opposing alliances of up to 3 teams each. Alliances should have the same number of robots. An alliance may have up to 2 human drivers for each robot and any number of human players. The total number of humans on the largest alliance must not exceed the smallest alliance by more than one person.

Field

The field requires a flat, open area at least 50 feet by 50 feet. The surface may vary; a paved parking lot or basketball court are recommended. Grass, dirt or slippery surfaces may limit the teams willing and able to play.

The area of play for the robots is within a circle 100 feet in circumference. At the center of the circle is the goal, a weighted rubber garbage can with an open top. The circle is divided into equal size sectors, one for each alliance.

The area of play for humans is outside a concentric circle 125 feet in circumference. The gap between the two circles is a safety zone that may not be entered by robots or humans.

It is not critical that the circles are perfectly shaped or the goal is in the exact center. The field must be marked in chalk, paint, tape, electrical extension cords, garden hoses or some other easily visible material less than 1" high. All teams must agree to the field.

Game Pieces

Each alliance has three flags and three balls.

A flag is a cube or regular tetrahedron with 8 inch edges. It must be an open lattice formed by smooth plastic tubing 1" to 2" in diameter. Vision tracking aids such as paint or tape may coat the tubing.

A ball is a size 3 or size 1 soccer ball or similar substitute. It must be inflated to a normal pressure. All balls must be marked to show the owning alliance.

Time

Matches are variable duration. The recommended maximum length is 150 seconds, however teams may agree to longer or unlimited duration. A match begins with 15 seconds of auton play followed by teleop play.

Starting Positions

Robots begin play within their alliance's sector and touching the circle. Flags begin play also within the sector, but touching the goal or another flag. Balls start in the human area, but enter play during teleop.

Auton Play

Alliances attempt to clear all flags from their sectors. Immediately upon clearing all flags from its sector, an alliance's ball is removed as if it had been put into the goal. Drivers may not control robots during auton.

Teleop Play

Alliances attempt to clear all flags from their sectors and put balls into the goal. When all flags are clear from its sector, an alliance's ball may enter play. Human players can throw or bounce the ball into the goal, or give it to a robot or to another human player. Robots may use any technique to put the ball into the goal.

Once a ball is in play, it remains in play until put into the goal. An alliance may have only one ball in play at a time. An alliance is not allowed to control the ball of another alliance. A robot may not control both a flag and a ball at the same time.

Robots and humans may go anywhere in their respective areas. Defensive play is permitted, but contact with an opposing alliance's ball is restricted to passive deflections.

Clearing Flags

A flag counts as being cleared from a sector if it is being carried clear of the ground or if it is completely outside the sector and still within the robot playing area. A robot causing a flag to leave the robot playing area is treated as having a flag in their sector until the flag is returned to play.

A flag that leaves the robot playing area must be returned to play near the point it exited play by a human player on the alliance that caused the flag to exit play.

[EricH]

Just as a suggestion, I would have a diameter or radius measurement on the circle, as well as the circumference. For some reason those are a lot easier to measure/mark. (Convenience, not particularly required.)

I would also have some minor questions on items that--for some reason--get stuck in between the two circles, if neither human nor robot can enter them. Simply: How do they re-enter play? But... I would advise a simple solution of a long-ish hook, and 1 HP per alliance at any time being the "designated retriever" of any item in that area, to either pull the item to the HPs (ball) or push it back into play (flag).


And one final item: If an alliance happens to drop one or more of their flags into the goal, is the flag in question considered as cleared or in that alliance's sector? Just a *bit* of a loophole that I can see pretty clearly, could have an impact on gameplay.

[kenfox]

Originally Posted by EricH

Just as a suggestion, I would have a diameter or radius measurement on the circle

Good idea. We've been using a 100' electrical cord laid on the ground. If we were using chalk it would make sense to sweep it out on a string.

I would also have some minor questions on items that--for some reason--get stuck in between the two circles, if neither human nor robot can enter them. Simply: How do they re-enter play?

The github project has some safety and miscellaneous rules, but loopholes are something I'm worried about so I didn't include them here. Right now we allow human players to briefly enter the safety zone to retrieve an item. I like your idea to push them back in with a broom or something, although human players with poles might be less safe than just picking them up?

And one final item: If an alliance happens to drop one or more of their flags into the goal, is the flag in question considered as cleared or in that alliance's sector? Just a *bit* of a loophole that I can see pretty clearly, could have an impact on gameplay.

I think we'd consider the flag outside the field, so the team putting the flag into the goal would not be able to put any more balls into play since a human player would not be able to put the flag back into play.

[EricH]

Originally Posted by kenfox

The github project has some safety and miscellaneous rules, but loopholes are something I'm worried about so I didn't include them here. Right now we allow human players to briefly enter the safety zone to retrieve an item. I like your idea to push them back in with a broom or something, although human players with poles might be less safe than just picking them up?

Depends somewhat on the pole/broom design, I think. Could do something out of lightweight PVC, 5' or so long. I don't see this being all that much different than the trident from 2010.

I think we'd consider the flag outside the field, so the team putting the flag into the goal would not be able to put any more balls into play since a human player would not be able to put the flag back into play.

There's a good closing of loophole.

[GeeTwo]

I had read the rules from github, but I didn't quite get the game flow until I saw the version above.

Is the sector clear just when your own flags are removed, or do all flags of all alliances have to be outside of the sector (or carried off the ground) to get a ball? Can robots control flags of the other alliances? Can robots control multiple flags at the same time? If the answers are what I think they are (all, yes, yes) I see a possible choke hold strategy - designing a robot that surrounds a bunch of flags but does not carry them off the floor, and can put down legs (or better yet, lift its wheels so it's sitting on its frame on the carpet - with a rubber strip for traction). Then, pile all the flags inside and park in the other alliance's sector (or on the line between two sectors).

On the neutral zone issue: if your "stick" were a regular push broom, and you add the rule that it can only be in the "neutral zone" when the bristles are on the floor (at both ends), this should be safer than having players enter the neutral zone.

[kenfox]

A sector is clear only when all flags are cleared. An alliance can control any flag, not just their own. A robot can control multiple flags. You guessed all the answers the way we intended.

Originally Posted by GeeTwo

I see a possible choke hold strategy - designing a robot that surrounds a bunch of flags but does not carry them off the floor, and can put down legs ... pile all the flags inside and park in the other alliance's sector (or on the line between two sectors).

Ouch! You are right. Any ideas how to solve that? Maybe treat any flag entering a robot's frame perimeter as if it left the field? It still doesn't eliminate a robot locking on to flags and sitting there though.

We're trying to make the flags a highly contested game piece that can be manipulated in a variety of ways.

On the neutral zone issue: if your "stick" were a regular push broom, and you add the rule that it can only be in the "neutral zone" when the bristles are on the floor (at both ends), this should be safer than having players enter the neutral zone.

I like it. Plus it gives teams a reason to bring brooms to clean the field.

[EricH]

Originally Posted by kenfox

Ouch! You are right. Any ideas how to solve that? Maybe treat any flag entering a robot's frame perimeter as if it left the field? It still doesn't eliminate a robot locking on to flags and sitting there though.

We're trying to make the flags a highly contested game piece that can be manipulated in a variety of ways.

Proposal, given the desired "highly contested" nature of the beast:

Any robot possessing more than 3 flags at a time will be considered to have a minimum of one flag in its alliance's sector until it releases at least one flag.

For this rule, possession is defined as: controlling the movement of the flag such that no other robot can reasonably get to it. Herding and bulldozing do not count as possession; carrying, trapping, and surrounding do. Nothing prevents a robot possessing 3 flags from pushing more flags around, provided that it does not take possession of them.


(Note: I picked 3 because it allows an alliance to deal with all of its own in one shot, but still forces them to contend with whatever their opponents are pushing into their sector.)

[GeeTwo]

Another possibility would be that any flags controlled by a robot outside of its own sector is considered "cleared" of all sectors, even if it is on the carpet.