Here I show how you can put your DEC tokens into Splinterlands.
1 Buy some DEC on https://leodex.io/market/DEC
You can get a BOOSTER PACK for about 3.3133 HIVE worth of DEC right now.
2 Login at https://splinterlands.com with your Hive account.
Click on the Dark Energy Crystal balance on the top right side.
3 Enter the amount of DEC tokens you have purchased, and select HIVE ENGINE wallet. (You can also select Binance Smart Chain if you have wrapped DEC on there.)
4 Sign the TX and you are golden!