Rules to level up

[matt-dray]

Let's keep this simple. Levelling up should be related to XP accumulation (#24).

What should the XP thresholds be? Might depend on how long we expect people to interact with the pet. Over multiple days, weeks, etc? Probably want the thresholds to be met relatively quickly to maintain some interest.

How many thresholds should there be and how should they scale? Might be more engaging if its non-linear. You can level up the first time relatively easily, then it takes a bit more effort, then a lot more effort.

Levelling up results in the pet taking a new form (#10) and more power in battle (#8)?

(Don't think about this too hard; no-one is actually going to play with this package.)

[matt-dray]

.update_blueprint() has current defaults of:

• xp_threshold_1 = 100L (i.e. need 100 XP to get from level 0 to level 1)
• xp_threshold_2 = 200L
• xp_threshold_3 = 500L

This feels okay in basic testing. You aren't likely to interact with the pet all the time and so it may take a few days to break the thresholds. It would probably be boring if it took months and it would reduce the reward of 'caring' for the pet if it broke the thresholds too quickly.

Aside: should probably provide an arbitrary number of thresholds in a list or vector rather than specifically-named variables. But three thresholds feels right.