The Rules

Game mechanics here

The Dice Kosmosaur is a d6 dice pool game made from an attribute and any relevant roll modifiers (discussed below). The the highest single die determines the action's outcome.
* 1 is a critical failure, you fail and things get worse
* 2-3 is a failure and you don't succeed but the situation changes and new opportunities arise
* 4-5 is a partial success; you get what you want but with a complication
* 6 is a complete success

If you get more than one 6, you may choose one of the following bonus effects:
* Cause additional effects appropriate to the task, gear and circumstances of the task.
* Reduce the time needed to accomplish the task by half.
* Secure an extra d6 to your next Task Roll.
* Grant an extra d6 to the next Task Roll of an ally.
* Add a new narrative element to the story appropriate to the character’s background and situation.

Kosmosaurs uses playing-facing rolls, meaning the GM never rolls, players will roll to both attack and defend.

Attributes and Roll Modifiers There are only two stats: Kosmo and Saur. Kosmo is your mental stat and Saur is your physical stat. You get 5 points to distribute among these two attributes, with 1 point being 1d6 in your pool. Your dinosaur species, role, gear, and knowledges can also grant you bonus or penalty dice.
* Choose 3 things you are good at and 1 thing you are bad at. These have to be things that are relevant and likely to happen in a game, but can represent an inherent ability (such as flying), talent, profession, or a hobby. You get +1d6 for things you are good at, and a -1d6 for what you are bad at.
* You can carry a number of items equal to your Saur score. These should be interesting or impactful items, weapons, armor, or gear that help distinguish you. Whenever you use this item in a roll, add +1d6
* You have a number of Knowledges equal to your Kosmo score. These can represent training, study, or experience. Add +1d6 whenever your Knowledge s relevant to a check.

Combat Combat works similarly to the rules above, but some results have more specific outcomes. Combat initiatives are usually determined organically. If it is unclear and initiative is rolled, then:
* 1 Frozen: The PCs are caught by surprise and don’t act on the first round, only rolling to defend themselves.
* 2-3 Slower: The enemies are faster than the PCs and act first. That means the PCs will roll to Defend themselves first, and then they attack.
* 4-5 Simultaneous: The PCs and their enemies act at the same time. That means the effects of their actions happen together.
* 6 Faster: The PCs are faster than their enemies and they act first. This means they can Attack first and then Defend themselves.

For attacking:
* 1 Fumble: Your attack fails spectacularly, and something happens that makes it impossible to make the same attack again in this combat (the weapon breaks, the argument is discarded).
* 2-3 Miss: Your attack simply misses the target completely.
* 4-5 Hit: Your attack hits your opponent and causes 1 Damage, but you open yourself for their attacks, reducing your next Defend test by -1d6.
* 6 Solid Hit: You attack hits decisively and cause 1 Damage.

For defending:
* 1 Step Into Attack: You try to avoid an attack and walk right into it. You take 2 Damage.
* 2-3 Hit: You fail to avoid your enemy’s attack and take 1 Damage.
* 4-5 Close Miss: You avoided the attack but it was a close call. You get distracted, however, and the next time you Defend you do it with -1d6 penalty.
* 6 Miss: You avoid the attack completely.

Damage If your Kosmosaur takes enough Damage, they can be Taken Out. If you even have more Damage Marks than points in your Attribute, you need to make an Attribute test, reducing the number of dice you roll by how many Marks you have over your Attribute score. The result will be determined in accordance with the following table.
* 1 Completely Out: You are Taken Out and nothing can bring you back in this scene, no matter how hard your allies try.
* 2-3 Taken Out: You are Taken Out and cannot act again until someone successfully helps you get back on your feet.
* 4-5 Not OK: You avoided the attack but it was a close call. You get distracted, however, and the next time you Defend you do it with -1d6 penalty.
* 6 Keep Going: You just buckle up and keep going, no matter how bad things are.

You can choose to avoid damage by sacrificing either Gear (for physical damage) or Knowledges (for mental damage). The gear becomes broken and the knowledge becomes temporarily forgotten until you have a chance to recover. The time depends on when it makes sense in the narrative.

I think this covers everything you need. If you have any rules questions post them here!

Sorry. I'm not clear on what happens if I don't want to sacrifice gear or knowledge and accept the damage?

You just mark a tick box under the appropriate stat. You can take damage equal to your stat before suffering any penalties. Physical damage will always be Saur.