Hi, and as everyone is saying, yes you can do all of that with Scripting (and even with just Variables and Link Restrictions too if Scripting seem daunting at the moment.
Using your Speed Variable Example
Set up your SPEED Variable
Then set up your in-game modifiers for the Speed Variable off Links and such. For example, set SPEED to start the game at a value of 1. Then later, maybe an event adds +2, and a Speed Potion temporarily adds +5 (if the player has found it yet).
To do it with Link and Variables Only:
In the case where you want to see if the player is fast enough to escape something, just create your outcome pages (say a page for ‘Escape’ & a page for ‘Getting Caught’)
On the Links that lead to each Page, just Name both ‘Try to Escape’ and Restrict them not to show - like this:
Link to Escape: SPEED > 3
Link to Getting Caught: Speed < 4
This way, if the player’s SPEED is 3 or less, the Try to Escape Link goes to Getting Caught; while if the player’s SPEED is 4 or more the same-looking Link (try to escape) goes to the Escape page.
To do it with Scripting:
You just need 1 Link called ‘Try to Escape’ without any Link Restrictions.
Then on the Link Script ( := ) you would use something like this:
IF %SPEED > 3 THEN
$DEST := @P100
IF %SPEED < 4 THEN
$DEST := @P200
This way, it does the same as the Link example above, but checks off one Link and sends the player to the correct page depending on the SPEED Variable value (where page 100 is Getting Caught & page 200 is Escape).