@spaceseeker19: Shotgun Diaries is way less crunchy than the one you're playing right now, which says a lot since the one you're playing right now isn't crunchy at all. Shotgun Diaries almost is more like a storytelling game than a traditional RPG.
The basic character creation mechanics is you make a Survivor by giving it a name and selecting from different Archetype: Clever (they're brainy and rely on their wits), Strong (they're brawny and rely on their muscles), Dangerous (they're fighters and rely on their weapons), Sneaky (they slippery and rely on their shadows), Fast (they're quick and rely on their legs) and Helpless (they're useless and rely on everyone else). That's basically character creation...
The basic gameplay mechanics is the GM narrates the story. Any time your Survivors need to fight/survive zombies, you roll dice (hopefully); and any time you're rolling dice, your Survivors are fighting/surviving a zombie attack. So you don't usually need to mess with dice unless you're being attacked by zombies. Everything else is just free narrative. After the GM narrates what's happening in a situation where a survival roll is going to be needed, the players decide how their characters plan on getting out of the bind they're in. If a character takes some action that compliments their Archetype they roll 4d6, and if any die rolls a 6 the action was a success. If they can't act in some sort of way that compliments their archetype, they get zero dice to roll, therefore success is impossible. If a survivor rolls successfully the player narrates how their survivor got out of the mess: maybe the Dangerous character grabbed his shotgun and blasted his way out of the mall, while the Sneaky character crawled underneath all the cars in the parking lot until they were clear of the horde, and the fast character simply shucked and jived and weaved through the crowd avoiding clawing hands until they got back out in the open freeway. If they fail to succeed in a survival roll, either because they had no dice to roll in the first place, or because they did get dice but failed to roll a 6, the narrator says what happened (which is usually that your survivor dies gruesomely; and luckily I allowed you to start the game with two survivors).
The game encourages the survivors to stick together as much as possible by giving any survivor one extra die to roll for every other survivor in their vicinity who is helping them complete a task in some way... So if a character makes a survival roll that compliments their archetype and there's two other characters present who are directly or indirectly assisting on some way they would roll 6d6 (4d6 for acting in accordance with their archetype and 1d6 for each other survivor). Whereas, if the other two survivors are attempting that same action but it is not not accordance with their archetypes, they still get to roll 2d6 (0d6 for their action being outside their archetype, but 1d6 for each of the other survivors with them). This is the only way a survivor can succeed in a roll that doesn't fall in accordance with their archetype, and it's the only way a Helpless survivor can succeed anything at all. Helpless survivors have to have other survivors around to get any dice to do anything at all.
While player cohesiveness is beneficial to the survivors, the player's should be aware that sometimes it is in the best interests of survivors to stick together to take advantage of the dice bonuses they get from assistance, while other times they need to cut their losses and bail on their survivors in order to save their own butts. Other times, because of a built-in fear mechanic the games uses, players may want to stick together and help their fellow survivors, but because of fear any successful roll causes a character to survive but to flee in panic, abandoning their friends to fend for themselves.
Characters can find sanctuary, which will give them a brief reprieve from the zombie assaults as well as sometimes give them "supplies" which get put into a community pool and can be taken from any player to act as bonus dice available to be used on a roll. Characters can also use those supplies to give them tools and weapons which lower the roll necessary to succeed.
Meanwhile a Zombie Clock ticks away. As the Zombie Clock gets higher and higher the GM can use the time earned to cause bad things to happen to the group. Also when the Zombie Clock Total gets higher than the sanctuary level the survivors are hiding in, the sanctuary is overrun and chaos ensues with all the characters trying to survive and still stick together.
Which leads to the question asked by @foolsmask. In regular games a timer is set and every ten minutes the Zombie Clock goes up by one while the Sanctuary defenses go down by one. Since we can't do that in a PbP game, and this is the first time I've tried running Shotgun Diaries in a PbP, I'm going to say that every week the game is going on in real life, the Zombie Clock goes up by 1. I think this will actually work nicely, since the purpose of the Zombie Clock in Shotgun Diaries is to keep the game moving along quickly, and by allowing the clock to tick by according to how much time has passed IRL in this PbP the players are encouraged to post a little more so as to get more stuff accomplished before the Zombie Clock gets so high thing go to Hell in a handbasket. I'm thinking one week per Zombie Clock bump should be sufficient. If I'm wrong, at least I'll know if it should be faster or slower next time around.