diff --git a/changelog.md b/changelog.md
index 9eb2e2b..d5e716d 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,7 +1,8 @@
 # The Modding Tree changelog:
 
-## v2.1: Non-nonsensical - 10/x/20
-- Moved most of the code users will want to edit to mod.js.
+## v2.1: We should have thought of this sooner! - 10/17/20
+- Moved most of the code users will want to edit to mod.js, added documentation for it.
+    - Specifically, modInfo, VERSION, canGenPoints, getPointGen, and maxTickLength
 - Added getStartPoints()
 - Added the ability to store non-layer-related data
 - Added the ability to display more things at the top of the tree tab below points.
diff --git a/docs/!general-info.md b/docs/!general-info.md
index ceb90dd..4d1e17b 100644
--- a/docs/!general-info.md
+++ b/docs/!general-info.md
@@ -25,6 +25,7 @@ All display text can be basic HTML instead (But you can't use most Vue features
 ## Table of Contents:
 
 - [Getting Started](getting-started.md): Getting your own copy of the code set up with Github Desktop.
+- [Main mod info](main-mod-info.md): How to set up general things for your mod in mod.js.
 - [Basic layer breakdown](basic-layer-breakdown.md): Breaking down the components of a layer with minimal features.
 - [Layer features](layer-features.md): Explanations of all of the different properties that you can give a layer.
 - [Upgrades](upgrades.md): How to create upgrades for a layer.
diff --git a/docs/main-mod-info.md b/docs/main-mod-info.md
new file mode 100644
index 0000000..759bbbe
--- /dev/null
+++ b/docs/main-mod-info.md
@@ -0,0 +1,61 @@
+# mod.js
+
+All of the code and data that you're likely to edit is here in mod.js! Everything in mod.js
+will not be altered by updates, besides the addition of new things.
+
+Here's a breakdown of what's in it:
+
+
+- modInfo is where most of the basic configuration for the mod is. It contains:
+    - name: The name of your mod. (a string)
+    - id: The id for your mod, a unique string that is used to determine savefile location. Setting it is important!
+    - pointsName: This changes what is displayed instead of "points" for the main currency. (It does not affect it in the code.)
+    - discordName, discordLink: If you have a Discord server or other discussion place, you can add a link to it.
+                "discordName" is the text on the link, and "discordLink" is the url of an invite.
+                If you're using a Discord invite, please make sure it's set to never expire.
+    - changelogLink: You can use this to set a link to a page where your changelog for the game is displayed.
+    - offlineLimit: The maximum amount of offline time that the player can accumulate, in hours. Any extra time is lost. (a number)
+                    This is useful because most of these mods are fast-paced enough that too much offline time ruins the balance,
+                    such as the time in between updates.
+                    That is why I suggest developers disable offline time on their own savefile.
+    - initialStartPoints: A Decimal for the amount of points a new player should start with.
+
+- VERSION is used to describe the current version of your mod. It contains:
+    num: The mod's version number, displayed at the top right of the tree tab.
+    name: The version's name, displayed alongside the number in the info tab.
+
+- doNotCallTheseFunctionsEveryTick is very important. TMT calls every function anywhere in "layers" every tick to store the result,
+        unless specifically told not to. Functions that have are used to do an action need to be identified. "Official" functions
+        (those in the documentation) are all fine, but if you make any new ones, add their names to this array.
+
+```js
+// (The ones here are examples, all official functions are already taken care of)
+var doNotCallTheseFunctionsEveryTick = ["doReset", "buy", "onPurchase", "blowUpEverything"]
+```
+
+- getStartPoints(): A function to determine the amount of points the player starts with after a reset. (returns a Decimal value)
+
+- canGenPoints(): A function returning a boolean for if points should be generated.
+        Use this if you want an upgrade to unlock generating points. 
+
+- getPointGen(): A function that calculates your points per second. Anything that affects your point gain should go into the calculation here.
+
+- addedPlayerData(): A function that returns any non-layer-related data that you want to be added to the save data and "player" object.
+
+```js
+function addedPlayerData() { return {
+	weather: "Yes",
+	happiness: new Decimal(72),
+}}
+```
+
+- displayThings: An array of functions used to display extra things at the top of the tree tab. Each function returns a string, which
+        is a line to display (with basic HTML support). If a function returns nothing, nothing is displayed (and it doesn't take up a line).
+
+- isEndgame(): A function to determine if the player has reached the end of the game, at which point the "you win!" screen appears.
+
+
+Less important things beyond this point!
+
+- maxTickLength(): Returns the maximum tick length, in milliseconds. Only really useful if you have something that reduces over time,
+        which long ticks mess up (usually a challenge).
\ No newline at end of file
diff --git a/js/utils.js b/js/utils.js
index a380a08..4d3535b 100644
--- a/js/utils.js
+++ b/js/utils.js
@@ -90,11 +90,12 @@ function startPlayerBase() {
 
 function getStartPlayer() {
 	playerdata = startPlayerBase()
-	extradata = addedPlayerData()
-
-	for (thing in extradata)
-		playerdata[thing] = extradata[thing]
-
+	
+	if (addedPlayerData) {
+		extradata = addedPlayerData()
+		for (thing in extradata)
+			playerdata[thing] = extradata[thing]
+	}
 	for (layer in layers){
 		playerdata[layer] = layers[layer].startData()
 		playerdata[layer].buyables = getStartBuyables(layer)